Problem 5 of Third round - Divisibility of a^n+b^n+c^n+d^n
Source: VI International Festival of Young Mathematicians Sozopol, Theme for 10-12 grade
December 24, 2019
number theoryDivisibilityprimes
Problem Statement
Let be a prime number. The natural numbers are such that and are divisible by . Prove that for all odd , is divisible by .