This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A175456 #8 Nov 21 2013 12:50:01
%S A175456 0,1,2,1,1,1,2,1,8,0,5,4,10,6,14,10,5,10,2,1,20,1,5,10,2,1,8,1,25,1,
%T A175456 11,10,23,1,22,1,30,10,17,10,14,19,20,19,26,20,34,1,11,1,50,26,13,19,
%U A175456 2,28,44,37,14,19,11,1,44,38,34,49,51,60,59,53,58,1,2,19,44,19,14,70,63,10,71,1,41,28,2,10,17,10,5,46,38,10,17,37,32,37,2,72,71,83
%N A175456 (Digit sum of 5^n) mod n.
%t A175456 Table[Mod[Total[IntegerDigits[5^n]],n],{n,100}] (* _Harvey P. Dale_, Jan 05 2012 *)
%Y A175456 Cf. A000351, A066001.
%K A175456 nonn,base
%O A175456 1,3
%A A175456 _N. J. A. Sloane_, Dec 03 2010