|
1. Multiples of 3 and 5
|
Candy Cane @ Thu, 12 Dec 2013,
Brian @ Thu, 30 May 2013,
99 Problems @ Mon, 29 Apr 2013,
Bumble Bee @ Thu, 27 Sep 2018,
Higi @ Mon, 29 Apr 2013,
Python @ Fri, 26 Feb 2016,
Method Man @ Thu, 31 May 2018,
The 26ers @ Thu, 28 Jul 2016,
Cauliflower @ Thu, 28 Jul 2016,
Dragon Fruit @ Mon, 29 Apr 2013,
PDV @ Fri, 26 Feb 2016,
Rock Solid @ Thu, 02 Apr 2015,
Team SNAP! @ Thu, 31 Mar 2016,
Persona 4 @ Thu, 30 Oct 2014,
Project Humbug @ Thu, 12 Dec 2013,
NASA @ Thu, 02 Apr 2015,
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
Team🍕 @ Wed, 28 Sep 2016,
Uno Punto @ Thu, 29 Aug 2013,
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
Team Beer @ Thu, 28 Aug 2014,
One Point @ Thu, 29 Aug 2013,
Four Balls @ Thu, 28 May 2015,
C# @ Thu, 29 Aug 2013,
Angry Armadillos @ Fri, 30 Jan 2015,
Night Salamander @ Thu, 31 May 2018,
Prime Triplets @ Thu, 11 May 2017,
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
PotionMasters @ Thu, 25 Sep 2014,
Jesscici @ Fri, 26 Feb 2016,
C++ @ Thu, 29 Aug 2013,
Geminy Cricket @ Thu, 28 May 2015,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
C @ Thu, 29 Aug 2013,
1 @ Thu, 27 Mar 2014,
Team this.Table @ Thu, 25 Jun 2015,
Precise Pangolin @ Thu, 29 May 2014,
ShanMan @ Thu, 30 May 2013,
Fünke @ Thu, 30 May 2013,
Sandstorm @ Thu, 30 Jan 2014,
Clojing Time @ Thu, 27 Feb 2014,
Clojurians @ Thu, 27 Aug 2015,
Not As Good As Clojure @ Thu, 29 Oct 2015,
Tits McGee @ Thu, 12 Dec 2013,
Kepler @ Thu, 30 May 2013
|
|
2. Even Fibonacci numbers
|
One Point @ Thu, 29 Aug 2013,
Geminy Cricket @ Thu, 28 May 2015,
Persona 4 @ Thu, 30 Oct 2014,
🏏 @ Thu, 29 Mar 2018,
Method Man @ Thu, 31 May 2018,
Team SNAP! @ Thu, 31 Mar 2016,
Precise Pangolin @ Thu, 29 May 2014,
Clojing Time @ Thu, 27 Feb 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
99 Problems @ Mon, 29 Apr 2013,
Dragon Fruit @ Mon, 29 Apr 2013,
Team🍕 @ Wed, 28 Sep 2016,
Higi @ Mon, 29 Apr 2013,
Brian @ Thu, 30 May 2013,
Kepler @ Thu, 30 May 2013,
PDV @ Fri, 26 Feb 2016,
NASA @ Thu, 02 Apr 2015,
Captain Squelch @ Thu, 27 Aug 2015,
ShanMan @ Thu, 30 May 2013,
Four Balls @ Thu, 28 May 2015,
Bumble Bee @ Thu, 27 Sep 2018,
C @ Thu, 29 Aug 2013,
C# @ Thu, 29 Aug 2013,
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
Not As Good As Clojure @ Thu, 29 Oct 2015,
Rock Solid @ Thu, 02 Apr 2015,
Tits McGee @ Thu, 12 Dec 2013,
Candy Cane @ Thu, 12 Dec 2013,
Sandstorm @ Thu, 30 Jan 2014,
We'll Tell You A Name Later @ Thu, 30 Jan 2014
|
|
3. Largest prime factor
|
🏏 @ Thu, 29 Mar 2018,
C# @ Thu, 29 Aug 2013,
Dragon Fruit @ Mon, 29 Apr 2013,
North West @ Thu, 27 Jun 2013,
The Iterators @ Thu, 28 Dec 2017,
Persona 4 @ Thu, 30 Oct 2014,
Not As Good As Clojure @ Thu, 29 Oct 2015,
EOF TABLE @ Thu, 28 Dec 2017,
Tits McGee @ Thu, 12 Dec 2013,
Chicken Burritos @ Thu, 27 Jun 2013,
Fudge Bar @ Thu, 27 Jun 2013,
Ruby Slippers @ Thu, 01 Aug 2013
|
|
4. Largest palindrome product
|
North West @ Thu, 27 Jun 2013,
Smitha @ Thu, 31 May 2018,
Angry Armadillos @ Fri, 30 Jan 2015,
99 Problems @ Mon, 29 Apr 2013,
Kepler @ Thu, 30 May 2013,
Chicken Burritos @ Thu, 27 Jun 2013,
Tits McGee @ Thu, 12 Dec 2013,
Persona 4 @ Thu, 30 Oct 2014
|
|
5. Smallest multiple
|
Bears @ Thu, 29 Aug 2013,
Smitha @ Thu, 31 May 2018,
Tits McGee @ Thu, 12 Dec 2013,
Team Beer @ Thu, 28 Aug 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
NASA @ Thu, 02 Apr 2015,
Strawberry Sample @ Thu, 29 May 2014,
Higi @ Mon, 29 Apr 2013,
North West @ Thu, 27 Jun 2013,
Sandstorm @ Thu, 30 Jan 2014
|
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6. Sum square difference
|
Team This Table @ Thu, 28 Aug 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
Sandstorm @ Thu, 30 Jan 2014,
Persona 4 @ Thu, 30 Oct 2014,
Smitha @ Thu, 31 May 2018,
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
North West @ Thu, 27 Jun 2013,
Bumble Bee @ Thu, 27 Sep 2018,
99 Problems @ Mon, 29 Apr 2013,
Tits McGee @ Thu, 12 Dec 2013,
Prime Triplets @ Thu, 11 May 2017,
C @ Thu, 29 Aug 2013,
Team Beer @ Thu, 28 Aug 2014,
Team Awesome @ Thu, 28 Aug 2014
|
|
7. 10001st prime
|
Team Beer @ Thu, 28 Aug 2014,
North West @ Thu, 27 Jun 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
The Julii @ Thu, 28 May 2015,
Smitha @ Thu, 28 Jun 2018,
Higi @ Mon, 29 Apr 2013,
Angry Armadillos @ Fri, 30 Jan 2015,
Swift @ Fri, 26 Feb 2016,
Team This Table @ Thu, 28 Aug 2014,
No Ether @ Thurs, 26 Feb 2015
|
|
8. Largest product in a series
|
Tits McGee @ Thu, 12 Dec 2013,
North West @ Thu, 27 Jun 2013,
C++ @ Thu, 29 Aug 2013,
Team f.lux @ Thu, 27 Oct 2016,
Team This Table @ Thu, 28 Aug 2014
|
|
9. Special Pythagorean triplet
|
Team 🐍 @ Thu, 27 Oct 2016,
Oiler @ Thu, 30 Jan 2014
|
|
10. Summation of primes
|
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
Team This Table @ Thu, 28 Aug 2014,
Swift @ Fri, 26 Feb 2016,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Tits McGee @ Thu, 12 Dec 2013,
North West @ Thu, 27 Jun 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
The Square Roots @ Fri, 30 Jan 2015,
Mountain Dew @ Thu, 29 May 2014,
Retro Secret Agents @ Thu, 30 Jan 2014,
Angry Armadillos @ Fri, 30 Jan 2015
|
|
11. Largest product in a grid
|
North West @ Thu, 27 Jun 2013,
Precise Pangolin @ Thu, 29 May 2014,
A.L.E.X. @ Thu, 27 Sep 2018,
Secret 🐿 @ Thu, 28 Dec 2017,
Team Huy @ Thu, 25 Jun 2015
|
|
12. Highly divisible triangular number
|
Secret 🐿++ @ Thu, 29 Jun 2017
|
|
13. Large sum
|
Secret 🐿++ @ Thu, 29 Jun 2017,
nerdBusters @ Wed, 19 Nov 2014,
Team Bernie @ Thu, 31 Jul 2014,
Team Beer @ Thu, 28 Aug 2014,
Team Awesome @ Thu, 28 Aug 2014,
AtomicAwesomePants @ Thu, 25 Sep 2014,
North West @ Thu, 27 Jun 2013
|
|
14. Longest Collatz sequence
|
C++ @ Thu, 26 Sep 2013,
North West @ Thu, 27 Jun 2013,
Team Awesome @ Thu, 28 Aug 2014,
Strawberry Sample @ Thu, 29 May 2014
|
|
15. Lattice paths
|
Chuckles @ Thu, 27 Aug 2015,
Back from Seoul @ Thu, 01 May 2014,
Prime Triplets @ Thu, 11 May 2017,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015
|
|
16. Power digit sum
|
The Square Roots @ Fri, 30 Jan 2015,
Team Bernie @ Thu, 31 Jul 2014,
Team Beer @ Thu, 28 Aug 2014,
99 Problems @ Mon, 29 Apr 2013,
FooBar @ Thu, 25 Oct 2018,
Oiler @ Thu, 30 Jan 2014,
AwesomeSauceChicken @ Thu, 25 Sep 2014
|
|
17. Number letter counts
|
Hot Sauce @ Thu, 30 Jan 2014,
Secret Squirrel @ Thu, 01 Sep 2016,
99 Problems @ Mon, 29 Apr 2013
|
|
18. Maximum path sum I
|
Project Humbug @ Thu, 12 Dec 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
Secret 🐿++ @ Thu, 27 Sep 2018
|
|
19. Counting Sundays
|
Joshua @ Thu, 29 May 2014,
Cell Jammers @ Thu, 27 Sep 2018,
Awesome Monster @ Thu, 01 May 2014,
Diablo @ Thu, 27 Feb 2014
|
|
20. Factorial digit sum
|
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Oiler @ Thu, 30 Jan 2014,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015,
Team Awesome @ Thu, 28 Aug 2014,
Team Bernie @ Thu, 31 Jul 2014,
Team Beer @ Thu, 28 Aug 2014,
Ghostbusters @ Fri, 30 Jan 2015,
Awesome Monster @ Thu, 01 May 2014,
99 Problems @ Mon, 29 Apr 2013,
Cell Jammers @ Thu, 27 Sep 2018,
Let's Roll @ Thu, 27 Sep 2018,
Kepler @ Thu, 30 May 2013
|
|
21. Amicable numbers
|
The 26ers @ Thu, 28 Jul 2016,
Tits McGee @ Thu, 12 Dec 2013,
No Ether @ Thurs, 26 Feb 2015,
U of I @ Thu, 01 Aug 2013,
Project Humbug @ Thu, 12 Dec 2013,
The 43ers @ Thu, 28 Jan 2016,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015
|
|
22. Names scores
|
Let's Roll @ Thu, 27 Sep 2018,
Started From The Bottom @ Fri, 30 Jan 2015,
Team Bernie @ Thu, 31 Jul 2014,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
We'll Tell You A Name Later @ Thu, 30 Jan 2014
|
|
23. Non-abundant sums
|
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014
|
|
24. Lexicographic permutations
|
Team Awesome @ Thu, 28 Aug 2014
|
|
25. 1000-digit Fibonacci number
|
Chicken Burritos @ Thu, 27 Jun 2013,
Diablo @ Thu, 27 Feb 2014,
The Steves @ Thu, 30 Jan 2014,
Kitten Sprinkles @ Thu, 27 Aug 2015,
The Unknowns @ Thu, 26 May 2016,
Secret 🐿 @ Wed, 28 Sep 2016,
North West @ Thu, 27 Jun 2013,
Kepler @ Thu, 30 May 2013,
99 Problems @ Mon, 29 Apr 2013,
Oiler @ Thu, 30 Jan 2014,
Team Awesome @ Thu, 28 Aug 2014,
Nameless @ Thu, 31 Jul 2014,
Awesome Monster @ Thu, 01 May 2014
|
|
26. Reciprocal cycles
|
The 26ers @ Thu, 28 Jul 2016
|
|
27. Quadratic primes
|
🍝🍝🍝 @ Wed, 28 Sep 2016
|
|
28. Number spiral diagonals
|
SubjectiveC @ Thu, 25 Sep 2014
|
|
29. Distinct powers
|
Awesome Monster @ Thu, 01 May 2014,
Chicken Burritos @ Thu, 27 Jun 2013
|
|
30. Digit fifth powers
|
3 @ Thu, 27 Mar 2014,
Chicken Burritos @ Thu, 27 Jun 2013,
C++ @ Thu, 29 Aug 2013,
99 Problems @ Mon, 29 Apr 2013,
Team Bernie @ Thu, 31 Jul 2014
|
|
31. Coin sums
|
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
R Marks The Spot @ Thu, 31 May 2018,
Kepler @ Thu, 30 May 2013,
Chicken Burritos @ Thu, 27 Jun 2013
|
|
32. Pandigital products
|
|
|
33. Digit canceling fractions
|
Secret 🐿 @ Thu, 26 Jan 2017
|
|
34. Digit factorials
|
AtomicAwesomePants @ Thu, 25 Sep 2014,
C++ @ Thu, 29 Aug 2013,
Team Awesome @ Thu, 28 Aug 2014,
Oiler @ Thu, 30 Jan 2014,
C++ @ Thu, 26 Sep 2013,
Chicken Burritos @ Thu, 27 Jun 2013
|
|
35. Circular primes
|
Team This Table @ Thu, 28 Aug 2014
|
|
36. Double-base palindromes
|
SubjectiveC @ Thu, 25 Sep 2014,
Team Awesome @ Thu, 28 Aug 2014,
I got %d problems but a %s ain't one @ Thu, 01 May 2014
|
|
37. Truncatable primes
|
SubjectiveC @ Thu, 25 Sep 2014,
Veggiecadres @ Wed, 19 Nov 2014
|
|
38. Pandigital multiples
|
SubjectiveC @ Thu, 25 Sep 2014
|
|
39. Integer right triangles
|
Project Humbug @ Thu, 12 Dec 2013
|
|
40. Champernowne's constant
|
Spencer @ Thu, 28 Jul 2016
|
|
41. Pandigital prime
|
FooBar @ Thu, 25 Oct 2018,
The Triad @ Thu, 17 Aug 2017,
Spencer @ Thu, 28 Jul 2016
|
|
42. Coded triangle numbers
|
Chuckles @ Thu, 27 Aug 2015,
Spencer @ Thu, 28 Jul 2016,
Secret 🐿 @ Thu, 12 Oct 2017
|
|
43. Sub-string divisibility
|
The 43ers @ Thu, 28 Jan 2016
|
|
44. Pentagon numbers
|
Nameless @ Thu, 31 Jul 2014
|
|
45. Triangular, pentagonal, and hexagonal
|
Secret 🐿 @ Thu, 27 Oct 2016
|
|
46. Goldbach's other conjecture
|
Chicken Burritos @ Thu, 27 Jun 2013
|
|
47. Distinct primes factors
|
C++ @ Thu, 29 Aug 2013,
ℚ² @ Thu, 29 Jun 2017
|
|
48. Self powers
|
AtomicAwesomePants @ Thu, 25 Sep 2014,
Honeybadger Don't Care @ Thu, 29 May 2014,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Fünke @ Thu, 30 May 2013,
99 Problems @ Mon, 29 Apr 2013,
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
Team This Table @ Thu, 28 Aug 2014,
Awesome Monster @ Thu, 01 May 2014,
Chicken Burritos @ Thu, 27 Jun 2013,
Oiler @ Thu, 30 Jan 2014,
Let's Roll @ Thu, 27 Sep 2018,
The Square Roots @ Fri, 30 Jan 2015,
North West @ Thu, 27 Jun 2013,
Ghostbusters @ Fri, 30 Jan 2015,
3 @ Thu, 27 Mar 2014
|
|
49. Prime permutations
|
Higi @ Mon, 29 Apr 2013,
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
Team This Table @ Thu, 28 Aug 2014,
3 @ Thu, 27 Mar 2014
|
|
50. Consecutive prime sum
|
Project Humbug @ Thu, 12 Dec 2013,
Team This Table @ Thu, 28 Aug 2014,
Chicken Burritos @ Thu, 27 Jun 2013
|
|
51. Prime digit replacements
|
|
|
52. Permuted multiples
|
Back from Seoul @ Thu, 01 May 2014,
3 @ Thu, 27 Mar 2014,
Oiler @ Thu, 30 Jan 2014,
The Steves @ Thu, 30 Jan 2014,
Higi @ Mon, 29 Apr 2013,
Team This Table @ Thu, 28 Aug 2014,
Secret 🐿 @ Thu, 12 Oct 2017
|
|
53. Combinatoric selections
|
Back from Seoul @ Thu, 01 May 2014,
Kitten Sprinkles @ Thu, 27 Aug 2015,
Just For Fun @ Mon, 29 Apr 2013,
Oiler @ Thu, 30 Jan 2014,
Project Humbug @ Thu, 12 Dec 2013,
The Chargers @ Thu, 15 Jun 2017
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|
54. Poker hands
|
|
|
55. Lychrel numbers
|
1 2 3 4 @ Thu, 30 May 2013,
The Chargers @ Thu, 15 Jun 2017
|
|
56. Powerful digit sum
|
Nameless @ Thu, 31 Jul 2014,
Oiler @ Thu, 30 Jan 2014,
Secret 🐿 @ Thu, 12 Oct 2017,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
We Hate Primes @ Thu, 27 Mar 2014
|
|
57. Square root convergents
|
|
|
58. Spiral primes
|
|
|
59. XOR decryption
|
Fünke @ Thu, 30 May 2013,
Secret 🐿 @ Thu, 27 Oct 2016
|
|
60. Prime pair sets
|
|
|
61. Cyclical figurate numbers
|
Mickey @ Thu, 28 Dec 2017
|
|
62. Cubic permutations
|
Mickey @ Thu, 28 Dec 2017,
The Chargers @ Thu, 15 Jun 2017
|
|
63. Powerful digit counts
|
🐿+🐢 @ Thu, 14 Sep 2017,
Mickey @ Thu, 28 Dec 2017
|
|
64. Odd period square roots
|
|
|
65. Convergents of e
|
|
|
66. Diophantine equation
|
|
|
67. Maximum path sum II
|
Just For Fun @ Mon, 29 Apr 2013,
Secret 🐿++ @ Thu, 27 Sep 2018,
Honeybadger Don't Care @ Thu, 29 May 2014,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
Project Humbug @ Thu, 12 Dec 2013,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015
|
|
68. Magic 5-gon ring
|
|
|
69. Totient maximum
|
Infinite Sadness @ Thu, 30 Apr 2015,
Lone Prime @ Thu, 15 Jun 2017
|
|
70. Totient permutation
|
|
|
71. Ordered fractions
|
JavaScript Evangelists @ Thu, 27 Sep 2018
|
|
72. Counting fractions
|
|
|
73. Counting fractions in a range
|
🦖+🐿 @ Thu, 25 Oct 2018
|
|
74. Digit factorial chains
|
|
|
75. Singular integer right triangles
|
|
|
76. Counting summations
|
|
|
77. Prime summations
|
|
|
78. Coin partitions
|
|
|
79. Passcode derivation
|
Team 🐍 @ Thu, 27 Oct 2016,
Fünke @ Thu, 30 May 2013
|
|
80. Square root digital expansion
|
|
|
81. Path sum: two ways
|
Bill @ Thu, 25 Oct 2018,
Awesome Monster @ Thu, 01 May 2014,
Emerald Vipers @ Thu, 30 Apr 2015
|
|
82. Path sum: three ways
|
Mountain Dew @ Thu, 29 May 2014
|
|
83. Path sum: four ways
|
|
|
84. Monopoly odds
|
|
|
85. Counting rectangles
|
sp00ky @ Thu, 26 Oct 2017,
Secret 🐿 @ Thu, 29 Mar 2018,
No, Sam! @ Thu, 29 Mar 2018,
Ａｅｓｔｈｅｔｉｃ @ Thu, 29 Mar 2018,
Awesome Monster @ Thu, 01 May 2014
|
|
86. Cuboid route
|
|
|
87. Prime power triples
|
0^0 @ Thu, 25 May 2017,
Oiler @ Thu, 30 Jan 2014
|
|
88. Product-sum numbers
|
|
|
89. Roman numerals
|
🍝🍝🍝 @ Wed, 28 Sep 2016
|
|
90. Cube digit pairs
|
Madelines @ Thu, 12 Oct 2017
|
|
91. Right triangles with integer coordinates
|
|
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92. Square digit chains
|
Lone Prime @ Thu, 15 Jun 2017,
We Hate Primes @ Thu, 27 Mar 2014,
Kepler @ Thu, 30 May 2013,
AtomicAwesomePants @ Thu, 25 Sep 2014,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
A.L.E.X. @ Thu, 27 Sep 2018
|
|
93. Arithmetic expressions
|
|
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94. Almost equilateral triangles
|
|
|
95. Amicable chains
|
Lone Prime @ Thu, 15 Jun 2017
|
|
96. Su Doku
|
|
|
97. Large non-Mersenne prime
|
Kepler @ Thu, 30 May 2013,
Angry Armadillos @ Fri, 30 Jan 2015,
Squirrels @ Thu, 02 Apr 2015,
Secret 🐿 @ Thu, 12 Oct 2017,
Username @ Thu, 30 May 2013,
The Triad @ Thu, 17 Aug 2017,
Fünke @ Thu, 30 May 2013,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Fabulous Five @ Thu, 27 Jul 2017
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|
98. Anagramic squares
|
The Redshirts @ Thu, 30 Oct 2014
|
|
99. Largest exponential
|
No, Sam! @ Thu, 29 Mar 2018
|
|
100. Arranged probability
|
|
|
101. Optimum polynomial
|
|
|
102. Triangle containment
|
CII @ Thu, 30 Mar 2017,
Team 1 @ Thu, 16 Nov 2017
|
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103. Special subset sums: optimum
|
|
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104. Pandigital Fibonacci ends
|
Good Democracy @ Thu, 26 Oct 2017
|
|
105. Special subset sums: testing
|
|
|
106. Special subset sums: meta-testing
|
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107. Minimal network
|
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|
108. Diophantine reciprocals I
|
|
|
109. Darts
|
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|
110. Diophantine reciprocals II
|
|
|
111. Primes with runs
|
|
|
112. Bouncy numbers
|
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Secret 🐿 @ Thu, 11 May 2017,
Team Danny @ Thu, 28 Aug 2014,
HashBit @ Thu, 31 Mar 2016,
Infinite Sadness @ Thu, 30 Apr 2015,
Angry Armadillos @ Fri, 30 Jan 2015,
Better Than Clojure @ Thu, 29 Oct 2015,
99 Problems @ Mon, 29 Apr 2013,
Three Minutes @ Thu, 27 Apr 2017
|
|
113. Non-bouncy numbers
|
|
|
114. Counting block combinations I
|
Just Add One! @ Thu, 01 Sep 2016
|
|
115. Counting block combinations II
|
|
|
116. Red, green or blue tiles
|
|
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117. Red, green, and blue tiles
|
|
|
118. Pandigital prime sets
|
|
|
119. Digit power sum
|
|
|
120. Square remainders
|
ℚ² @ Thu, 29 Jun 2017,
No @ Thu, 25 May 2017,
max(pow(e,r)) @ Thu, 28 Aug 2014,
Good Democracy @ Thu, 26 Oct 2017
|
|
121. Disc game prize fund
|
🐿+🐢 @ Thu, 28 Jun 2018
|
|
122. Efficient exponentiation
|
|
|
123. Prime square remainders
|
|
|
124. Ordered radicals
|
|
|
125. Palindromic sums
|
Team Beer @ Thu, 28 Aug 2014
|
|
126. Cuboid layers
|
|
|
127. abc-hits
|
|
|
128. Hexagonal tile differences
|
|
|
129. Repunit divisibility
|
|
|
130. Composites with prime repunit property
|
|
|
131. Prime cube partnership
|
|
|
132. Large repunit factors
|
|
|
133. Repunit nonfactors
|
|
|
134. Prime pair connection
|
|
|
135. Same differences
|
|
|
136. Singleton difference
|
|
|
137. Fibonacci golden nuggets
|
|
|
138. Special isosceles triangles
|
|
|
139. Pythagorean tiles
|
|
|
140. Modified Fibonacci golden nuggets
|
|
|
141. Investigating progressive numbers, n, which are also square.
|
|
|
142. Perfect Square Collection
|
|
|
143. Investigating the Torricelli point of a triangle
|
|
|
144. Investigating multiple reflections of a laser beam.
|
Ａｅｓｔｈｅｔｉｃ @ Thu, 29 Mar 2018
|
|
145. How many reversible numbers are there below one-billion?
|
Diophantine @ Thu, 14 Sep 2017,
Codew @ Thu, 27 Jul 2017
|
|
146. Investigating a Prime Pattern
|
|
|
147. Rectangles in cross-hatched grids
|
|
|
148. Exploring Pascal's triangle.
|
Sierpiński’s 🧀 @ Thu, 26 Jan 2017
|
|
149. Searching for a maximum-sum subsequence.
|
|
|
150. Searching a triangular array for a sub-triangle having minimum-sum.
|
|
|
151. Paper sheets of standard sizes: an expected-value problem.
|
|
|
152. Writing 1/2 as a sum of inverse squares
|
|
|
153. Investigating Gaussian Integers
|
|
|
154. Exploring Pascal's pyramid.
|
|
|
155. Counting Capacitor Circuits.
|
|
|
156. Counting Digits
|
|
|
157. Solving the diophantine equation 1/a+1/b= p/10n
|
|
|
158. Exploring strings for which only one character comes lexicographically after its neighbour to the left.
|
👨💻 @ Thu, 23 Feb 2017
|
|
159. Digital root sums of factorisations.
|
|
|
160. Factorial trailing digits
|
|
|
161. Triominoes
|
|
|
162. Hexadecimal numbers
|
|
|
163. Cross-hatched triangles
|
|
|
164. Numbers for which no three consecutive digits have a sum greater than a given value.
|
Cell Jammers @ Thu, 27 Sep 2018
|
|
165. Intersections
|
|
|
166. Criss Cross
|
|
|
167. Investigating Ulam sequences
|
|
|
168. Number Rotations
|
|
|
169. Exploring the number of different ways a number can be expressed as a sum of powers of 2.
|
Teamshawarma @ Thu, 26 Oct 2017,
EOF TABLE @ Thu, 28 Dec 2017
|
|
170. Find the largest 0 to 9 pandigital that can be formed by concatenating products.
|
|
|
171. Finding numbers for which the sum of the squares of the digits is a square.
|
|
|
172. Investigating numbers with few repeated digits.
|
|
|
173. Using up to one million tiles how many different 'hollow' square laminae can be formed?
|
The Hardware Problems @ Thu, 17 Aug 2017,
Pier Revue @ Thu, 27 Apr 2017
|
|
174. Counting the number of 'hollow' square laminae that can form one, two, three, ... distinct arrangements.
|
|
|
175. Fractions involving the number of different ways a number can be expressed as a sum of powers of 2.
|
|
|
176. Right-angled triangles that share a cathetus.
|
|
|
177. Integer angled Quadrilaterals.
|
|
|
178. Step Numbers
|
|
|
179. Consecutive positive divisors
|
Prime Triplets @ Thu, 11 May 2017,
MAD @ Fri, 26 Feb 2016,
The Hardware Problems @ Thu, 17 Aug 2017
|
|
180. Rational zeros of a function of three variables.
|
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181. Investigating in how many ways objects of two different colours can be grouped.
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182. RSA encryption
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183. Maximum product of parts
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184. Triangles containing the origin.
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185. Number Mind
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186. Connectedness of a network.
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187. Semiprimes
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Team Fast @ Thu, 31 May 2018,
Good Democracy @ Thu, 26 Oct 2017,
Cauliflower @ Thu, 28 Jul 2016
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188. The hyperexponentiation of a number
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189. Tri-colouring a triangular grid
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190. Maximising a weighted product
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191. Prize Strings
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Young Diagram @ Thu, 28 Jan 2016
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192. Best Approximations
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193. Squarefree Numbers
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MICKEY🐭 @ Thu, 26 Apr 2018
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194. Coloured Configurations
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195. Inscribed circles of triangles with one angle of 60 degrees
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196. Prime triplets
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197. Investigating the behaviour of a recursively defined sequence
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198. Ambiguous Numbers
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199. Iterative Circle Packing
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200. Find the 200th prime-proof sqube containing the contiguous sub-string '200'
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201. Subsets with a unique sum
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202. Laserbeam
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No-eyed Dear @ Thu, 12 Oct 2017
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203. Squarefree Binomial Coefficients
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Sierpiński’s 🧀 @ Thu, 28 Jun 2018
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204. Generalised Hamming Numbers
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205. Dice Game
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Programmers Just Want To Have Fun @ Thu, 30 Apr 2015,
Team Fast @ Thu, 31 May 2018,
I don't know, dude. @ Thu, 30 Nov 2017,
AbstractSolutionFactorie @ Thu, 26 May 2016,
Icosahedral Cats @ Thu, 28 Sep 2017,
Awesome @ Thu, 02 Apr 2015,
Team 🐍 @ Thu, 27 Oct 2016
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206. Concealed Square
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Team Beer @ Thu, 28 Aug 2014,
Sierpiński’s 🧀 @ Thu, 27 Jul 2017,
Awesome @ Thu, 02 Apr 2015,
Squirrels @ Thu, 02 Apr 2015,
DynamicDuo @ Wed, 19 Nov 2014,
AtomicAwesomePants @ Thu, 25 Sep 2014,
Team Fast @ Thu, 31 May 2018,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Angry Armadillos @ Fri, 30 Jan 2015
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207. Integer partition equations
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208. Robot Walks
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209. Circular Logic
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210. Obtuse Angled Triangles
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211. Divisor Square Sum
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212. Combined Volume of Cuboids
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213. Flea Circus
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214. Totient Chains
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215. Crack-free Walls
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216. Investigating the primality of numbers of the form 2n2-1
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217. Balanced Numbers
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218. Perfect right-angled triangles
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219. Skew-cost coding
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220. Heighway Dragon
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221. Alexandrian Integers
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222. Sphere Packing
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223. Almost right-angled triangles I
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224. Almost right-angled triangles II
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225. Tribonacci non-divisors
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226. A Scoop of Blancmange
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227. The Chase
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228. Minkowski Sums
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229. Four Representations using Squares
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230. Fibonacci Words
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231. The prime factorisation of binomial coefficients
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232. The Race
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233. Lattice points on a circle
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234. Semidivisible numbers
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235. An Arithmetic Geometric sequence
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236. Luxury Hampers
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237. Tours on a 4 x n playing board
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238. Infinite string tour
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239. Twenty-two Foolish Primes
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240. Top Dice
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241. Perfection Quotients
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242. Odd Triplets
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243. Resilience
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Pier Revue @ Thu, 27 Apr 2017
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244. Sliders
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245. Coresilience
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246. Tangents to an ellipse
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247. Squares under a hyperbola
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248. Numbers for which Euler’s totient function equals 13!
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249. Prime Subset Sums
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250. 250250
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251. Cardano Triplets
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252. Convex Holes
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253. Tidying up
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254. Sums of Digit Factorials
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255. Rounded Square Roots
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256. Tatami-Free Rooms
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257. Angular Bisectors
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258. A lagged Fibonacci sequence
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259. Reachable Numbers
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260. Stone Game
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261. Pivotal Square Sums
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262. Mountain Range.
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263. An engineers' dream come true
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264. Triangle Centres
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265. Binary Circles
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266. Pseudo Square Root
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267. Billionaire
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268. Counting numbers with at least four distinct prime factors less than 100
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269. Polynomials with at least one integer root
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270. Cutting Squares
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271. Modular Cubes, part 1
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272. Modular Cubes, part 2
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273. Sum of Squares
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274. Divisibility Multipliers
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275. Balanced Sculptures
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276. Primitive Triangles
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277. A Modified Collatz sequence
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278. Linear Combinations of Semiprimes
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279. Triangles with integral sides and an integral angle
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280. Ant and seeds
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281. Pizza Toppings
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282. The Ackermann function
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283. Integer sided triangles for which the area/perimeter ratio is integral.
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284. Steady Squares
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285. Pythagorean odds
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286. Scoring probabilities
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287. Quadtree encoding (a simple compression algorithm)
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288. An enormous factorial
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289. Eulerian Cycles
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290. Digital Signature
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291. Panaitopol Primes
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292. Pythagorean Polygons
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293. Pseudo-Fortunate Numbers
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294. Sum of digits - experience #23
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295. Lenticular holes
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296. Angular Bisector and Tangent
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297. Zeckendorf Representation
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298. Selective Amnesia
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|
299. Three similar triangles
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|
300. Protein folding
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|
|
301. Nim
|
Easily Distracted @ Thu, 28 Sep 2017,
Young Diagram @ Thu, 28 Jan 2016
|
|
302. Strong Achilles Numbers
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|
303. Multiples with small digits
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|
|
304. Primonacci
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|
|
305. Reflexive Position
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|
|
306. Paper-strip Game
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|
|
307. Chip Defects
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|
|
308. An amazing Prime-generating Automaton
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|
|
309. Integer Ladders
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|
|
310. Nim Square
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|
311. Biclinic Integral Quadrilaterals
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|
|
312. Cyclic paths on Sierpiński graphs
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|
313. Sliding game
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|
|
314. The Mouse on the Moon
|
|
|
315. Digital root clocks
|
|
|
316. Numbers in decimal expansions
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|
317. Firecracker
|
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|
318. 2011 nines
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|
319. Bounded Sequences
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|
|
320. Factorials divisible by a huge integer
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|
|
321. Swapping Counters
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|
|
322. Binomial coefficients divisible by 10
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|
|
323. Bitwise-OR operations on random integers
|
Sierpiński’s 🧀 @ Thu, 27 Jul 2017,
Fabulous Five @ Thu, 27 Jul 2017
|
|
324. Building a tower
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|
325. Stone Game II
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|
|
326. Modulo Summations
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|
327. Rooms of Doom
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|
328. Lowest-cost Search
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|
|
329. Prime Frog
|
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|
330. Euler's Number
|
|
|
331. Cross flips
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|
332. Spherical triangles
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|
333. Special partitions
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|
334. Spilling the beans
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|
335. Gathering the beans
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|
336. Maximix Arrangements
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|
337. Totient Stairstep Sequences
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|
338. Cutting Rectangular Grid Paper
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|
|
339. Peredur fab Efrawg
|
|
|
340. Crazy Function
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|
|
341. Golomb's self-describing sequence
|
|
|
342. The totient of a square is a cube
|
|
|
343. Fractional Sequences
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|
|
344. Silver dollar game
|
|
|
345. Matrix Sum
|
Coca-Cola® @ Thu, 25 May 2017
|
|
346. Strong Repunits
|
|
|
347. Largest integer divisible by two primes
|
|
|
348. Sum of a square and a cube
|
|
|
349. Langton's ant
|
|
|
350. Constraining the least greatest and the greatest least
|
|
|
351. Hexagonal orchards
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|
352. Blood tests
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|
353. Risky moon
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|
354. Distances in a bee's honeycomb
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|
355. Maximal coprime subset
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|
|
356. Largest roots of cubic polynomials
|
|
|
357. Prime generating integers
|
No Ether @ Thurs, 26 Feb 2015
|
|
358. Cyclic numbers
|
|
|
359. Hilbert's New Hotel
|
|
|
360. Scary Sphere
|
|
|
361. Subsequence of Thue-Morse sequence
|
|
|
362. Squarefree factors
|
|
|
363. Bézier Curves
|
|
|
364. Comfortable distance
|
|
|
365. A huge binomial coefficient
|
|
|
366. Stone Game III
|
|
|
367. bozo sort
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|
|
368. A Kempner-like series
|
|
|
369. Badugi
|
|
|
370. Geometric triangles
|
|
|
371. Licence plates
|
|
|
372. Pencils of rays
|
|
|
373. Circumscribed Circles
|
|
|
374. Maximum Integer Partition Product
|
|
|
375. Minimum of subsequences
|
|
|
376. Nontransitive sets of dice
|
|
|
377. Sum of digits, experience 13
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|
|
378. Triangle Triples
|
|
|
379. Least common multiple count
|
|
|
380. Amazing Mazes!
|
|
|
381. (prime-k) factorial
|
Deer F. Kennedy @ Thu, 30 Nov 2017
|
|
382. Generating polygons
|
|
|
383. Divisibility comparison between factorials
|
|
|
384. Rudin-Shapiro sequence
|
|
|
385. Ellipses inside triangles
|
|
|
386. Maximum length of an antichain
|
|
|
387. Harshad Numbers
|
The PinPals @ Thu, 25 Jun 2015
|
|
388. Distinct Lines
|
|
|
389. Platonic Dice
|
The Hardware Problems @ Thu, 17 Aug 2017
|
|
390. Triangles with non rational sides and integral area
|
|
|
391. Hopping Game
|
|
|
392. Enmeshed unit circle
|
|
|
393. Migrating ants
|
|
|
394. Eating pie
|
|
|
395. Pythagorean tree
|
|
|
396. Weak Goodstein sequence
|
|
|
397. Triangle on parabola
|
|
|
398. Cutting rope
|
|
|
399. Squarefree Fibonacci Numbers
|
|
|
400. Fibonacci tree game
|
|
|
401. Sum of squares of divisors
|
|
|
402. Integer-valued polynomials
|
|
|
403. Lattice points enclosed by parabola and line
|
|
|
404. Crisscross Ellipses
|
|
|
405. A rectangular tiling
|
|
|
406. Guessing Game
|
|
|
407. Idempotents
|
|
|
408. Admissible paths through a grid
|
|
|
409. Nim Extreme
|
|
|
410. Circle and tangent line
|
|
|
411. Uphill paths
|
|
|
412. Gnomon numbering
|
|
|
413. One-child Numbers
|
|
|
414. Kaprekar constant
|
|
|
415. Titanic sets
|
|
|
416. A frog's trip
|
|
|
417. Reciprocal cycles II
|
|
|
418. Factorisation triples
|
|
|
419. Look and say sequence
|
|
|
420. 2x2 positive integer matrix
|
|
|
421. Prime factors of n15+1
|
|
|
422. Sequence of points on a hyperbola
|
|
|
423. Consecutive die throws
|
|
|
424. Kakuro
|
|
|
425. Prime connection
|
|
|
426. Box-ball system
|
|
|
427. n-sequences
|
|
|
428. Necklace of circles
|
|