MathDB

4

Part of 1995 Mexico National Olympiad

Problems(1)

26 elements of {1,2,3,.. ,40} such that product of 2of them is never square

Source: Mexican Mathematical Olympiad 1995 OMM P4

7/28/2018
Find 2626 elements of {1,2,3,...,40}\{1, 2, 3, ... , 40\} such that the product of two of them is never a square. Show that one cannot find 2727 such elements.
number theoryPerfect Square