MathDB

Difference=gcd

Source: Singapore MO 2011 senior round 2 Q2

June 25, 2011

number theorygreatest common divisorleast common multiplenumber theory proposed

Problem Statement

Determine if there is a set

S

of 2011 positive integers so that for every pair

m,n

of distinct elements of

S

|m-n|=(m,n)

. Here

(m,n)

denotes the greatest common divisor of

m

and

n