MathDB
arithmetic progressions

Source: 2011 Romania TST Problem 2

February 4, 2012
floor functionpigeonhole principlearithmetic sequenceRamsey Theorynumber theory proposednumber theory

Problem Statement

Prove that the set S={nπn=0,1,2,3,}S=\{\lfloor n\pi\rfloor \mid n=0,1,2,3,\ldots\} contains arithmetic progressions of any finite length, but no infinite arithmetic progressions.
Vasile Pop