MathDB
[To be solved] - Challenge Problem: number array

Source:

August 9, 2004
modular arithmetic

Problem Statement

Prove that there are no perfect squares in the array below: 111111111...222222222...333333333...444444444...555555555...666666666...777777777...888888888...999999999...\begin{array}{cccc}11&111&1111&...\\22&222&2222&...\\33&333&3333&...\\44&444&4444&...\\55&555&5555&... \\66&666&6666&...\\77&777&7777&...\\88&888&8888&...\\99&999&9999&...\end{array}