Sad Number Theory
Source: 2018 USAMO 3, by Ivan Borsenco
April 18, 2018
USAMO2018 USAMO Problem 3number theoryHi
Problem Statement
For a given integer , let be the set of positive integers less than that are relatively prime to . Prove that if every prime that divides also divides , then is divisible by for every positive integer . Proposed by Ivan Borsenco