Problem

Source: Argentina IMO TST 2007 problem 5

Tags: number theory unsolved, number theory



Let $ d_1,d_2 \ldots, d_r$ be the positive divisors of $ n$ $ 1=d_1<d_2< \ldots <d_r=n$ If $ (d_7)^2 + (d_{15})^2= (d_{16})^2$ find all posible values of $ d_{17}$