If we calculate a2 mod 6 for 0 a
5 we get: 0,1,4,3,4,1.
The largest value of a such that a2a mod 6 is 4.
Let's call M(n) the largest value of a n such that a2
a (mod n).
So M(6) = 4.
Find M(n) for 1
n
107.
These problems are part of Project Euler and are licensed under CC BY-NC-SA 2.0 UK