Constructing sets of positive integers
Source: European Girl's MO 2013, Problem 3
April 10, 2013
least common multiplenumber theoryCombinatorial Number TheoryEGMOEGMO 2013
Problem Statement
Let be a positive integer.(a) Prove that there exists a set of pairwise different positive integers, such that the least common multiple of any two elements of is no larger than .(b) Prove that every set of pairwise different positive integers contains two elements the least common multiple of which is larger than .