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 A117009 #3 Mar 30 2012 16:50:24 %S A117009 1,-1,2,-3,-4,2,9,-4,-8,2,5,2,2,0,2,-9,-4,2,-8,14,16,-11,-4,-8,2,-4, %T A117009 -20,16,19,2,2,-4,2,-8,-16,2,19,-8,-8,2,-4,16,2,16,2,-17,14,-24,-16, %U A117009 -4,2,2,-4,26,2,7,2,2,16,-20,-24,-4,16,-8,-24,2,25,-4,-8,16,8,2,2,8,2,2,-32,2,17,-4,2,-20,14,-32,2,-4,-24,36,16,48 %N A117009 A117000(8*n+1) + A117001(8*n-1). %D A117009 H. J. S. Smith, Report on the Theory of Numbers, reprinted in Vol. 1 of his Collected Math. Papers, Chelsea, NY, 1979, see p. 322. %K A117009 sign %O A117009 0,3 %A A117009 _N. J. A. Sloane_, Apr 15 2006