MathDB
Eventually linear

Source: Iranian National Olympiad (3rd Round) 2002

October 2, 2006
number theory proposednumber theory

Problem Statement

A subset SS of N\mathbb N is eventually linear iff there are k,NNk,N\in\mathbb N that for n>N,nSknn>N,n\in S\Longleftrightarrow k|n. Let SS be a subset of N\mathbb N that is closed under addition. Prove that SS is eventually linear.