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 A113322 #3 Mar 30 2012 18:50:53 %S A113322 1,2,-1,3,-1,4,-2,5,-4,6,-4,7,-6,8,-6,9,-7,10,-9,11,-9,12,-10,13,-12, %T A113322 14,-12,15,-14,16,-14,17,-15,18,-17,19,-17,20,-19,21,-19,22,-20,23, %U A113322 -22,24,-22,25,-23,26,-25,27,-25,28,-27,29,-27,30,-28,31,-30,32,-30,33,-31,34 %N A113322 First differences of A113321. %C A113322 a(n) = A113321(n+1) - A113321(n); %C A113322 A000027 is a subsequence: a(A004277(n-1)) = n. %K A113322 sign %O A113322 1,2 %A A113322 _Reinhard Zumkeller_, Oct 26 2005