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 A007738 #19 Feb 14 2014 00:33:51 %S A007738 1,1,1,2,4,1,1,2,3,4,10,2,12,1,4,2,16,3,3,4,1,10,22,2,4,12,9,2,7,4,15, %T A007738 4,10,16,4,6,9,3,12,4,40,1,6,10,12,22,23,2,1,4,16,12,26,9,20,2,3,7,29, %U A007738 4,60,15,3,8,12,10,66,16,22,4,70,6,24,9,4,6,10,12,78,4,27,40,41,2,16,6,7,10 %N A007738 Period of repeating digits of 1/n in base 7. %H A007738 T. D. Noe, <a href="/A007738/b007738.txt">Table of n, a(n) for n=1..1000</a> %H A007738 <a href="/index/1#1overn">Index entries for sequences related to decimal expansion of 1/n</a> %t A007738 f[n_] := MultiplicativeOrder[7, n/(7^IntegerExponent[n, 7])]; Array[f, 80] (* _Robert G. Wilson v_, Jun 10 2011 *) %o A007738 (PARI) a(n)=znorder(Mod(7,n/7^valuation(n,7))) \\ _Charles R Greathouse IV_, Jun 10 2011 %K A007738 nonn,base %O A007738 1,4 %A A007738 _N. J. A. Sloane_, Hal Sampson (hals(AT)easynet.com)