mn and (m + 1)(n + 1) are perfect squares , nice pair of pos. integers
Source: Tournament of Towns, Junior A-Level , Fall 2019 p5
April 20, 2020
Perfect SquaresPerfect Squarenumber theory
Problem Statement
Let us say that the pair of two positive different integers m and n is nice if and are perfect squares. Prove that for each positive integer m there exists at least one such that the pair is nice.(Yury Markelov)