Source: 2017 China Northern MO, Grade 11, Problem 4
February 24, 2020
number theory
Problem Statement
Positive intenger n≥3. a1,a2,⋯,an are n positive intengers that are pairwise coprime, satisfying that there exists k1,k2,⋯,kn∈{−1,1},∑i=1nkiai=0. Are there positive intengers b1,b2,⋯,bn, for any k∈Z+, b1+ka1,b2+ka2,⋯,bn+kan are pairwise coprime?