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 A112081 #2 Mar 31 2012 14:02:21 %S A112081 0,1,-1,0,2,0,4,-1,0,0,0,6,-3,0,6,0,1,-1,0,-3,0,9,-3,0,0,0,1,-3,0,-2, %T A112081 0,1,-1,0,9,0,1,-1,0,12,0,3,-1,0,0,0,3,-4,0,2,0,1,-1,0,-3,0,16,-3,0,0, %U A112081 0,1,-3,0,-5,0,1,-1,0,14,0,1,-1,0,2,0,19,-1,0,0,0,3,-3,0,2,0,1,-1,0 %N A112081 A112080(n)/2. %K A112081 sign %O A112081 1,5 %A A112081 _Antti Karttunen_, Aug 27 2005