IMO 2011 Shortlist N3

Let n ≥ 1 be an odd integer. Determine all functions f from the set of integers to itself such that for all integers x a...

IMO 2011 Shortlist N3

Category: Number Theory

Problem

Let n ≥ 1 be an odd integer. Determine all functions f from the set of integers to itself such that for all integers x and y the difference f(x) − f(y) divides xn − yn .