(1 + a^1)(1 + a^2)...(1 + a^{p - 1})\equiv 1 (mod q), if a^p \equiv 1 mod q
Source: 2020 Estonia TST 4.3
November 18, 2020
number theoryremainder
Problem Statement
The prime numbers and and the integer are chosen such that and (mod ), but (mod ). Prove that (mod ) .