MathDB

6

Part of 2015 Turkey MO (2nd round)

Problems(1)

2n^2 | a^n-1

Source: Turkey National Olympiad 2015 P6

12/14/2015
Find all positive integers nn such that for any positive integer aa relatively prime to nn, 2n2∣an−12n^2 \mid a^n - 1.
number theorynumber theory proposed