This article is from the Puzzles FAQ, by Chris Cole chris@questrel.questrel.com and Matthew Daly mwdaly@pobox.com with numerous contributions by others.
Is it possible to form two numbers A and B from 22 digits such that
A = B^2? Of course, leading digits must be non-zero.
arithmetic/digits/squares/length.22.s
No, the number of digits of A^2 must be of the form 3n or 3n-1.
 
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