Number of distinct quadratic residues mod 10^n = number of distinct n-digit endings of base 10 squares.
1, 6, 22, 159, 1044, 9121, 78132, 748719, 7161484, 70800861, 699869892
2 seqfan posts
Fri Aug 28 20:47:39 CEST 2009 [seqfan] Re: Looking for help with a formula