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 A176920 #4 Mar 31 2012 12:38:36
%S A176920 1,1,1,1,1,1,42,1,9,1,22,1,78,42,1,1,272,9,342,1,42,22,506,1,1,78,81,
%T A176920 42,812,1,465,1,22,272,42,9,111,342,78,1,205,42,903,22,9,506,2162,1,
%U A176920 2058,1,272,78,689,81,22,42,342,812,3422,1,3660,465,126,1,78,22,2211,272,506
%N A176920 Period of decimal representation of 1/n^2.
%C A176920 term #7=42; 1/7^2= 0. 020408163265306122448979591836734693877551` 020408163265306122448979591836734693877551` 020408163265306122448979591836734693877551` 02040816326530612244897959183673469..
%t A176920 DigitCycleLength[r_Rational,b_Integer?Positive]:=MultiplicativeOrder[b,FixedPoint[Quotient[ #,GCD[ #,b]]&,Denominator[r]]];Table[If[n<2,1,DigitCycleLength[1/n^2,10]],{n,5!}]
%Y A176920 Cf. A007732
%K A176920 nonn,base
%O A176920 1,7
%A A176920 _Vladimir Joseph Stephan Orlovsky_, Apr 29 2010