|
1. Multiples of 3 and 5
|
C++ @ Thu, 29 Aug 2013,
C @ Thu, 29 Aug 2013,
Team🍕 @ Wed, 28 Sep 2016,
Team SNAP! @ Thu, 31 Mar 2016,
PDV @ Fri, 26 Feb 2016,
Python @ Fri, 26 Feb 2016,
Prime Triplets @ Thu, 11 May 2017,
Team this.Table @ Thu, 25 Jun 2015,
Jesscici @ Fri, 26 Feb 2016,
Team Beer @ Thu, 28 Aug 2014,
Four Balls @ Thu, 28 May 2015,
Not As Good As Clojure @ Thu, 29 Oct 2015,
Tits McGee @ Thu, 12 Dec 2013,
Precise Pangolin @ Thu, 29 May 2014,
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
NASA @ Thu, 02 Apr 2015,
The 26ers @ Thu, 28 Jul 2016,
Persona 4 @ Thu, 30 Oct 2014,
Cauliflower @ Thu, 28 Jul 2016,
Rock Solid @ Thu, 02 Apr 2015,
Clojurians @ Thu, 27 Aug 2015,
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
99 Problems @ Mon, 29 Apr 2013,
Sandstorm @ Thu, 30 Jan 2014,
Candy Cane @ Thu, 12 Dec 2013,
1 @ Thu, 27 Mar 2014,
PotionMasters @ Thu, 25 Sep 2014,
Dragon Fruit @ Mon, 29 Apr 2013,
Geminy Cricket @ Thu, 28 May 2015,
Higi @ Mon, 29 Apr 2013,
Brian @ Thu, 30 May 2013,
Kepler @ Thu, 30 May 2013,
Project Humbug @ Thu, 12 Dec 2013,
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
Uno Punto @ Thu, 29 Aug 2013,
Clojing Time @ Thu, 27 Feb 2014,
Fünke @ Thu, 30 May 2013,
One Point @ Thu, 29 Aug 2013,
ShanMan @ Thu, 30 May 2013,
C# @ Thu, 29 Aug 2013,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Angry Armadillos @ Fri, 30 Jan 2015
|
|
2. Even Fibonacci numbers
|
Kepler @ Thu, 30 May 2013,
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
Sandstorm @ Thu, 30 Jan 2014,
99 Problems @ Mon, 29 Apr 2013,
C @ Thu, 29 Aug 2013,
Candy Cane @ Thu, 12 Dec 2013,
ShanMan @ Thu, 30 May 2013,
NASA @ Thu, 02 Apr 2015,
Four Balls @ Thu, 28 May 2015,
Geminy Cricket @ Thu, 28 May 2015,
Not As Good As Clojure @ Thu, 29 Oct 2015,
Clojing Time @ Thu, 27 Feb 2014,
Dragon Fruit @ Mon, 29 Apr 2013,
Captain Squelch @ Thu, 27 Aug 2015,
Tits McGee @ Thu, 12 Dec 2013,
C# @ Thu, 29 Aug 2013,
Team SNAP! @ Thu, 31 Mar 2016,
Team🍕 @ Wed, 28 Sep 2016,
Persona 4 @ Thu, 30 Oct 2014,
Rock Solid @ Thu, 02 Apr 2015,
PDV @ Fri, 26 Feb 2016,
Higi @ Mon, 29 Apr 2013,
One Point @ Thu, 29 Aug 2013,
Precise Pangolin @ Thu, 29 May 2014,
Brian @ Thu, 30 May 2013
|
|
3. Largest prime factor
|
C# @ Thu, 29 Aug 2013,
Persona 4 @ Thu, 30 Oct 2014,
Dragon Fruit @ Mon, 29 Apr 2013,
Tits McGee @ Thu, 12 Dec 2013,
Chicken Burritos @ Thu, 27 Jun 2013,
Ruby Slippers @ Thu, 01 Aug 2013,
Fudge Bar @ Thu, 27 Jun 2013,
North West @ Thu, 27 Jun 2013,
Not As Good As Clojure @ Thu, 29 Oct 2015
|
|
4. Largest palindrome product
|
Kepler @ Thu, 30 May 2013,
Persona 4 @ Thu, 30 Oct 2014,
Chicken Burritos @ Thu, 27 Jun 2013,
North West @ Thu, 27 Jun 2013,
Angry Armadillos @ Fri, 30 Jan 2015,
99 Problems @ Mon, 29 Apr 2013,
Tits McGee @ Thu, 12 Dec 2013
|
|
5. Smallest multiple
|
Strawberry Sample @ Thu, 29 May 2014,
Bears @ Thu, 29 Aug 2013,
Sandstorm @ Thu, 30 Jan 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
Team Beer @ Thu, 28 Aug 2014,
NASA @ Thu, 02 Apr 2015,
Higi @ Mon, 29 Apr 2013,
North West @ Thu, 27 Jun 2013,
Tits McGee @ Thu, 12 Dec 2013
|
|
6. Sum square difference
|
Prime Triplets @ Thu, 11 May 2017,
Team This Table @ Thu, 28 Aug 2014,
Team Awesome @ Thu, 28 Aug 2014,
Persona 4 @ Thu, 30 Oct 2014,
Team Beer @ Thu, 28 Aug 2014,
max(pow(e,r)) @ Thu, 28 Aug 2014,
99 Problems @ Mon, 29 Apr 2013,
North West @ Thu, 27 Jun 2013,
C @ Thu, 29 Aug 2013,
Tits McGee @ Thu, 12 Dec 2013,
Sandstorm @ Thu, 30 Jan 2014,
We'll Tell You A Name Later @ Thu, 30 Jan 2014
|
|
7. 10001st prime
|
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
Swift @ Fri, 26 Feb 2016,
No Ether @ Thurs, 26 Feb 2015,
The Julii @ Thu, 28 May 2015,
North West @ Thu, 27 Jun 2013,
Higi @ Mon, 29 Apr 2013,
Team Beer @ Thu, 28 Aug 2014,
Angry Armadillos @ Fri, 30 Jan 2015,
Team This Table @ Thu, 28 Aug 2014
|
|
8. Largest product in a series
|
Team f.lux @ Thu, 27 Oct 2016,
C++ @ Thu, 29 Aug 2013,
North West @ Thu, 27 Jun 2013,
Tits McGee @ Thu, 12 Dec 2013,
Team This Table @ Thu, 28 Aug 2014
|
|
9. Special Pythagorean triplet
|
Oiler @ Thu, 30 Jan 2014,
Team 🐍 @ Thu, 27 Oct 2016
|
|
10. Summation of primes
|
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
The Square Roots @ Fri, 30 Jan 2015,
North West @ Thu, 27 Jun 2013,
Mountain Dew @ Thu, 29 May 2014,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
Swift @ Fri, 26 Feb 2016,
Team This Table @ Thu, 28 Aug 2014,
Tits McGee @ Thu, 12 Dec 2013,
Angry Armadillos @ Fri, 30 Jan 2015,
Retro Secret Agents @ Thu, 30 Jan 2014,
We'll Tell You A Name Later @ Thu, 30 Jan 2014
|
|
11. Largest product in a grid
|
North West @ Thu, 27 Jun 2013,
Precise Pangolin @ Thu, 29 May 2014,
Team Huy @ Thu, 25 Jun 2015
|
|
12. Highly divisible triangular number
|
Secret 🐿++ @ Thu, 29 Jun 2017
|
|
13. Large sum
|
Team Bernie @ Thu, 31 Jul 2014,
nerdBusters @ Wed, 19 Nov 2014,
Secret 🐿++ @ Thu, 29 Jun 2017,
AtomicAwesomePants @ Thu, 25 Sep 2014,
Team Awesome @ Thu, 28 Aug 2014,
Team Beer @ Thu, 28 Aug 2014,
North West @ Thu, 27 Jun 2013
|
|
14. Longest Collatz sequence
|
Team Awesome @ Thu, 28 Aug 2014,
Strawberry Sample @ Thu, 29 May 2014,
North West @ Thu, 27 Jun 2013,
C++ @ Thu, 26 Sep 2013
|
|
15. Lattice paths
|
Prime Triplets @ Thu, 11 May 2017,
Chuckles @ Thu, 27 Aug 2015,
Back from Seoul @ Thu, 01 May 2014,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015
|
|
16. Power digit sum
|
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Team Bernie @ Thu, 31 Jul 2014,
99 Problems @ Mon, 29 Apr 2013,
Oiler @ Thu, 30 Jan 2014,
The Square Roots @ Fri, 30 Jan 2015,
Team Beer @ Thu, 28 Aug 2014
|
|
17. Number letter counts
|
Secret Squirrel @ Thu, 01 Sep 2016,
Hot Sauce @ Thu, 30 Jan 2014,
99 Problems @ Mon, 29 Apr 2013
|
|
18. Maximum path sum I
|
Project Humbug @ Thu, 12 Dec 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014
|
|
19. Counting Sundays
|
Diablo @ Thu, 27 Feb 2014,
Joshua @ Thu, 29 May 2014,
Awesome Monster @ Thu, 01 May 2014
|
|
20. Factorial digit sum
|
Team Beer @ Thu, 28 Aug 2014,
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
99 Problems @ Mon, 29 Apr 2013,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015,
Oiler @ Thu, 30 Jan 2014,
Ghostbusters @ Fri, 30 Jan 2015,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Team Bernie @ Thu, 31 Jul 2014,
Team Awesome @ Thu, 28 Aug 2014,
Awesome Monster @ Thu, 01 May 2014,
Kepler @ Thu, 30 May 2013
|
|
21. Amicable numbers
|
U of I @ Thu, 01 Aug 2013,
Tits McGee @ Thu, 12 Dec 2013,
Project Humbug @ Thu, 12 Dec 2013,
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015,
The 43ers @ Thu, 28 Jan 2016,
No Ether @ Thurs, 26 Feb 2015,
The 26ers @ Thu, 28 Jul 2016
|
|
22. Names scores
|
Team Bernie @ Thu, 31 Jul 2014,
Started From The Bottom @ Fri, 30 Jan 2015,
We'll Tell You A Name Later @ Thu, 30 Jan 2014,
Vegetarian Kernel Sanders @ Thu, 31 Jul 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
|
Oiler @ Thu, 30 Jan 2014,
99 Problems @ Mon, 29 Apr 2013,
North West @ Thu, 27 Jun 2013,
Nameless @ Thu, 31 Jul 2014,
The Steves @ Thu, 30 Jan 2014,
Team Awesome @ Thu, 28 Aug 2014,
Kepler @ Thu, 30 May 2013,
Secret 🐿 @ Wed, 28 Sep 2016,
Awesome Monster @ Thu, 01 May 2014,
Kitten Sprinkles @ Thu, 27 Aug 2015,
Chicken Burritos @ Thu, 27 Jun 2013,
Diablo @ Thu, 27 Feb 2014,
The Unknowns @ Thu, 26 May 2016
|
|
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
|
Chicken Burritos @ Thu, 27 Jun 2013,
Awesome Monster @ Thu, 01 May 2014
|
|
30. Digit fifth powers
|
Team Bernie @ Thu, 31 Jul 2014,
99 Problems @ Mon, 29 Apr 2013,
C++ @ Thu, 29 Aug 2013,
3 @ Thu, 27 Mar 2014,
Chicken Burritos @ Thu, 27 Jun 2013
|
|
31. Coin sums
|
Chicken Burritos @ Thu, 27 Jun 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014,
Kepler @ Thu, 30 May 2013
|
|
32. Pandigital products
|
|
|
33. Digit canceling fractions
|
Secret 🐿 @ Thu, 26 Jan 2017
|
|
34. Digit factorials
|
C++ @ Thu, 29 Aug 2013,
Team Awesome @ Thu, 28 Aug 2014,
Chicken Burritos @ Thu, 27 Jun 2013,
C++ @ Thu, 26 Sep 2013,
Oiler @ Thu, 30 Jan 2014,
AtomicAwesomePants @ Thu, 25 Sep 2014
|
|
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
|
Veggiecadres @ Wed, 19 Nov 2014,
SubjectiveC @ Thu, 25 Sep 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
|
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
|
|
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
|
Oiler @ Thu, 30 Jan 2014,
Chicken Burritos @ Thu, 27 Jun 2013,
Fünke @ Thu, 30 May 2013,
The Square Roots @ Fri, 30 Jan 2015,
99 Problems @ Mon, 29 Apr 2013,
AtomicAwesomePants @ Thu, 25 Sep 2014,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Ghostbusters @ Fri, 30 Jan 2015,
Honeybadger Don't Care @ Thu, 29 May 2014,
I got %d problems but a %s ain't one @ Thu, 01 May 2014,
Team This Table @ Thu, 28 Aug 2014,
North West @ Thu, 27 Jun 2013,
Awesome Monster @ Thu, 01 May 2014,
3 @ Thu, 27 Mar 2014
|
|
49. Prime permutations
|
Hung Like David Foster Wallace @ Thu, 12 Dec 2013,
3 @ Thu, 27 Mar 2014,
Team This Table @ Thu, 28 Aug 2014,
Higi @ Mon, 29 Apr 2013
|
|
50. Consecutive prime sum
|
Project Humbug @ Thu, 12 Dec 2013,
Chicken Burritos @ Thu, 27 Jun 2013,
Team This Table @ Thu, 28 Aug 2014
|
|
51. Prime digit replacements
|
|
|
52. Permuted multiples
|
Team This Table @ Thu, 28 Aug 2014,
Oiler @ Thu, 30 Jan 2014,
3 @ Thu, 27 Mar 2014,
Back from Seoul @ Thu, 01 May 2014,
The Steves @ Thu, 30 Jan 2014,
Higi @ Mon, 29 Apr 2013
|
|
53. Combinatoric selections
|
The Chargers @ Thu, 15 Jun 2017,
Kitten Sprinkles @ Thu, 27 Aug 2015,
Oiler @ Thu, 30 Jan 2014,
Back from Seoul @ Thu, 01 May 2014,
Project Humbug @ Thu, 12 Dec 2013,
Just For Fun @ Mon, 29 Apr 2013
|
|
54. Poker hands
|
|
|
55. Lychrel numbers
|
The Chargers @ Thu, 15 Jun 2017,
1 2 3 4 @ Thu, 30 May 2013
|
|
56. Powerful digit sum
|
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Nameless @ Thu, 31 Jul 2014,
We Hate Primes @ Thu, 27 Mar 2014,
Oiler @ Thu, 30 Jan 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
|
|
|
62. Cubic permutations
|
The Chargers @ Thu, 15 Jun 2017
|
|
63. Powerful digit counts
|
🐿+🐢 @ Thu, 14 Sep 2017
|
|
64. Odd period square roots
|
|
|
65. Convergents of e
|
|
|
66. Diophantine equation
|
|
|
67. Maximum path sum II
|
Project Humbug @ Thu, 12 Dec 2013,
Honeybadger Don't Care @ Thu, 29 May 2014,
Mighty Morphin' Power Angers @ Fri, 30 Jan 2015,
Just For Fun @ Mon, 29 Apr 2013,
Vegetarian Kernel Sanders @ Thu, 31 Jul 2014
|
|
68. Magic 5-gon ring
|
|
|
69. Totient maximum
|
Lone Prime @ Thu, 15 Jun 2017,
Infinite Sadness @ Thu, 30 Apr 2015
|
|
70. Totient permutation
|
|
|
71. Ordered fractions
|
|
|
72. Counting fractions
|
|
|
73. Counting fractions in a range
|
|
|
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
|
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
|
Awesome Monster @ Thu, 01 May 2014
|
|
86. Cuboid route
|
|
|
87. Prime power triples
|
Oiler @ Thu, 30 Jan 2014,
0^0 @ Thu, 25 May 2017
|
|
88. Product-sum numbers
|
|
|
89. Roman numerals
|
🍝🍝🍝 @ Wed, 28 Sep 2016
|
|
90. Cube digit pairs
|
|
|
91. Right triangles with integer coordinates
|
|
|
92. Square digit chains
|
Lone Prime @ Thu, 15 Jun 2017,
AtomicAwesomePants @ Thu, 25 Sep 2014,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Kepler @ Thu, 30 May 2013,
We Hate Primes @ Thu, 27 Mar 2014
|
|
93. Arithmetic expressions
|
|
|
94. Almost equilateral triangles
|
|
|
95. Amicable chains
|
Lone Prime @ Thu, 15 Jun 2017
|
|
96. Su Doku
|
|
|
97. Large non-Mersenne prime
|
Fünke @ Thu, 30 May 2013,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
Kepler @ Thu, 30 May 2013,
The Triad @ Thu, 17 Aug 2017,
Fabulous Five @ Thu, 27 Jul 2017,
Squirrels @ Thu, 02 Apr 2015,
Username @ Thu, 30 May 2013,
Angry Armadillos @ Fri, 30 Jan 2015
|
|
98. Anagramic squares
|
The Redshirts @ Thu, 30 Oct 2014
|
|
99. Largest exponential
|
|
|
100. Arranged probability
|
|
|
101. Optimum polynomial
|
|
|
102. Triangle containment
|
CII @ Thu, 30 Mar 2017
|
|
103. Special subset sums: optimum
|
|
|
104. Pandigital Fibonacci ends
|
|
|
105. Special subset sums: testing
|
|
|
106. Special subset sums: meta-testing
|
|
|
107. Minimal network
|
|
|
108. Diophantine reciprocals I
|
|
|
109. Darts
|
|
|
110. Diophantine reciprocals II
|
|
|
111. Primes with runs
|
|
|
112. Bouncy numbers
|
Better Than Clojure @ Thu, 29 Oct 2015,
Secret 🐿 @ Thu, 11 May 2017,
HashBit @ Thu, 31 Mar 2016,
Infinite Sadness @ Thu, 30 Apr 2015,
Three Minutes @ Thu, 27 Apr 2017,
Angry Armadillos @ Fri, 30 Jan 2015,
AwesomeSauceChicken @ Thu, 25 Sep 2014,
99 Problems @ Mon, 29 Apr 2013,
Team Danny @ Thu, 28 Aug 2014
|
|
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
|
|
|
117. Red, green, and blue tiles
|
|
|
118. Pandigital prime sets
|
|
|
119. Digit power sum
|
|
|
120. Square remainders
|
No @ Thu, 25 May 2017,
ℚ² @ Thu, 29 Jun 2017,
max(pow(e,r)) @ Thu, 28 Aug 2014
|
|
121. Disc game prize fund
|
|
|
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.
|
|
|
145. How many reversible numbers are there below one-billion?
|
Codew @ Thu, 27 Jul 2017,
Diophantine @ Thu, 14 Sep 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.
|
|
|
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.
|
|
|
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?
|
Pier Revue @ Thu, 27 Apr 2017,
The Hardware Problems @ Thu, 17 Aug 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
|
MAD @ Fri, 26 Feb 2016,
The Hardware Problems @ Thu, 17 Aug 2017,
Prime Triplets @ Thu, 11 May 2017
|
|
180. Rational zeros of a function of three variables.
|
|
|
181. Investigating in how many ways objects of two different colours can be grouped.
|
|
|
182. RSA encryption
|
|
|
183. Maximum product of parts
|
|
|
184. Triangles containing the origin.
|
|
|
185. Number Mind
|
|
|
186. Connectedness of a network.
|
|
|
187. Semiprimes
|
Cauliflower @ Thu, 28 Jul 2016
|
|
188. The hyperexponentiation of a number
|
|
|
189. Tri-colouring a triangular grid
|
|
|
190. Maximising a weighted product
|
|
|
191. Prize Strings
|
Young Diagram @ Thu, 28 Jan 2016
|
|
192. Best Approximations
|
|
|
193. Squarefree Numbers
|
|
|
194. Coloured Configurations
|
|
|
195. Inscribed circles of triangles with one angle of 60 degrees
|
|
|
196. Prime triplets
|
|
|
197. Investigating the behaviour of a recursively defined sequence
|
|
|
198. Ambiguous Numbers
|
|
|
199. Iterative Circle Packing
|
|
|
200. Find the 200th prime-proof sqube containing the contiguous sub-string '200'
|
|
|
201. Subsets with a unique sum
|
|
|
202. Laserbeam
|
|
|
203. Squarefree Binomial Coefficients
|
|
|
204. Generalised Hamming Numbers
|
|
|
205. Dice Game
|
Programmers Just Want To Have Fun @ Thu, 30 Apr 2015,
Awesome @ Thu, 02 Apr 2015,
Team 🐍 @ Thu, 27 Oct 2016,
AbstractSolutionFactorie @ Thu, 26 May 2016
|
|
206. Concealed Square
|
Team Beer @ Thu, 28 Aug 2014,
Angry Armadillos @ Fri, 30 Jan 2015,
Awesome @ Thu, 02 Apr 2015,
Sierpiński’s 🧀 @ Thu, 27 Jul 2017,
AtomicAwesomePants @ Thu, 25 Sep 2014,
Squirrels @ Thu, 02 Apr 2015,
DynamicDuo @ Wed, 19 Nov 2014,
AwesomeSauceChicken @ Thu, 25 Sep 2014
|
|
207. Integer partition equations
|
|
|
208. Robot Walks
|
|
|
209. Circular Logic
|
|
|
210. Obtuse Angled Triangles
|
|
|
211. Divisor Square Sum
|
|
|
212. Combined Volume of Cuboids
|
|
|
213. Flea Circus
|
|
|
214. Totient Chains
|
|
|
215. Crack-free Walls
|
|
|
216. Investigating the primality of numbers of the form 2n2-1
|
|
|
217. Balanced Numbers
|
|
|
218. Perfect right-angled triangles
|
|
|
219. Skew-cost coding
|
|
|
220. Heighway Dragon
|
|
|
221. Alexandrian Integers
|
|
|
222. Sphere Packing
|
|
|
223. Almost right-angled triangles I
|
|
|
224. Almost right-angled triangles II
|
|
|
225. Tribonacci non-divisors
|
|
|
226. A Scoop of Blancmange
|
|
|
227. The Chase
|
|
|
228. Minkowski Sums
|
|
|
229. Four Representations using Squares
|
|
|
230. Fibonacci Words
|
|
|
231. The prime factorisation of binomial coefficients
|
|
|
232. The Race
|
|
|
233. Lattice points on a circle
|
|
|
234. Semidivisible numbers
|
|
|
235. An Arithmetic Geometric sequence
|
|
|
236. Luxury Hampers
|
|
|
237. Tours on a 4 x n playing board
|
|
|
238. Infinite string tour
|
|
|
239. Twenty-two Foolish Primes
|
|
|
240. Top Dice
|
|
|
241. Perfection Quotients
|
|
|
242. Odd Triplets
|
|
|
243. Resilience
|
Pier Revue @ Thu, 27 Apr 2017
|
|
244. Sliders
|
|
|
245. Coresilience
|
|
|
246. Tangents to an ellipse
|
|
|
247. Squares under a hyperbola
|
|
|
248. Numbers for which Euler’s totient function equals 13!
|
|
|
249. Prime Subset Sums
|
|
|
250. 250250
|
|
|
251. Cardano Triplets
|
|
|
252. Convex Holes
|
|
|
253. Tidying up
|
|
|
254. Sums of Digit Factorials
|
|
|
255. Rounded Square Roots
|
|
|
256. Tatami-Free Rooms
|
|
|
257. Angular Bisectors
|
|
|
258. A lagged Fibonacci sequence
|
|
|
259. Reachable Numbers
|
|
|
260. Stone Game
|
|
|
261. Pivotal Square Sums
|
|
|
262. Mountain Range.
|
|
|
263. An engineers' dream come true
|
|
|
264. Triangle Centres
|
|
|
265. Binary Circles
|
|
|
266. Pseudo Square Root
|
|
|
267. Billionaire
|
|
|
268. Counting numbers with at least four distinct prime factors less than 100
|
|
|
269. Polynomials with at least one integer root
|
|
|
270. Cutting Squares
|
|
|
271. Modular Cubes, part 1
|
|
|
272. Modular Cubes, part 2
|
|
|
273. Sum of Squares
|
|
|
274. Divisibility Multipliers
|
|
|
275. Balanced Sculptures
|
|
|
276. Primitive Triangles
|
|
|
277. A Modified Collatz sequence
|
|
|
278. Linear Combinations of Semiprimes
|
|
|
279. Triangles with integral sides and an integral angle
|
|
|
280. Ant and seeds
|
|
|
281. Pizza Toppings
|
|
|
282. The Ackermann function
|
|
|
283. Integer sided triangles for which the area/perimeter ratio is integral.
|
|
|
284. Steady Squares
|
|
|
285. Pythagorean odds
|
|
|
286. Scoring probabilities
|
|
|
287. Quadtree encoding (a simple compression algorithm)
|
|
|
288. An enormous factorial
|
|
|
289. Eulerian Cycles
|
|
|
290. Digital Signature
|
|
|
291. Panaitopol Primes
|
|
|
292. Pythagorean Polygons
|
|
|
293. Pseudo-Fortunate Numbers
|
|
|
294. Sum of digits - experience #23
|
|
|
295. Lenticular holes
|
|
|
296. Angular Bisector and Tangent
|
|
|
297. Zeckendorf Representation
|
|
|
298. Selective Amnesia
|
|
|
299. Three similar triangles
|
|
|
300. Protein folding
|
|
|
301. Nim
|
Young Diagram @ Thu, 28 Jan 2016
|
|
302. Strong Achilles Numbers
|
|
|
303. Multiples with small digits
|
|
|
304. Primonacci
|
|
|
305. Reflexive Position
|
|
|
306. Paper-strip Game
|
|
|
307. Chip Defects
|
|
|
308. An amazing Prime-generating Automaton
|
|
|
309. Integer Ladders
|
|
|
310. Nim Square
|
|
|
311. Biclinic Integral Quadrilaterals
|
|
|
312. Cyclic paths on Sierpiński graphs
|
|
|
313. Sliding game
|
|
|
314. The Mouse on the Moon
|
|
|
315. Digital root clocks
|
|
|
316. Numbers in decimal expansions
|
|
|
317. Firecracker
|
|
|
318. 2011 nines
|
|
|
319. Bounded Sequences
|
|
|
320. Factorials divisible by a huge integer
|
|
|
321. Swapping Counters
|
|
|
322. Binomial coefficients divisible by 10
|
|
|
323. Bitwise-OR operations on random integers
|
Sierpiński’s 🧀 @ Thu, 27 Jul 2017,
Fabulous Five @ Thu, 27 Jul 2017
|
|
324. Building a tower
|
|
|
325. Stone Game II
|
|
|
326. Modulo Summations
|
|
|
327. Rooms of Doom
|
|
|
328. Lowest-cost Search
|
|
|
329. Prime Frog
|
|
|
330. Euler's Number
|
|
|
331. Cross flips
|
|
|
332. Spherical triangles
|
|
|
333. Special partitions
|
|
|
334. Spilling the beans
|
|
|
335. Gathering the beans
|
|
|
336. Maximix Arrangements
|
|
|
337. Totient Stairstep Sequences
|
|
|
338. Cutting Rectangular Grid Paper
|
|
|
339. Peredur fab Efrawg
|
|
|
340. Crazy Function
|
|
|
341. Golomb's self-describing sequence
|
|
|
342. The totient of a square is a cube
|
|
|
343. Fractional Sequences
|
|
|
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
|
|
|
352. Blood tests
|
|
|
353. Risky moon
|
|
|
354. Distances in a bee's honeycomb
|
|
|
355. Maximal coprime subset
|
|
|
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
|
|
|
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
|
|
|
378. Triangle Triples
|
|
|
379. Least common multiple count
|
|
|
380. Amazing Mazes!
|
|
|
381. (prime-k) factorial
|
|
|
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
|
|