mathguy
Posts:
12
Registered:
6/23/13


number problem
Posted:
Jun 23, 2013 3:14 AM


Can anyone prove the following: let S be a set of distinct integers with the property that (ab)^2 divides ab for distinct a,b in S. Show that the number of elements of S <= 5.
for example , {0,2,4} is such a set. I've coded a program to show that it's true for n <= 20000 where n is largest element of S, which is far from a proof though.

