E885:Erdős Problem #885 “Can k positive integers have at least k common factor differences for every k?”

3)V2Three positive integers have at least three common factor differences.

2)V2The positive integers 8 and 120 have at least two common factor differences, namely 2 and 7.

1)V1For every positive integer k, there are k distinct positive integers whose factor-difference sets have at lea…