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 A105996 #5 Mar 31 2012 13:21:09 %S A105996 1,2,4,11,41,222,1761,21064,386241,11044282,500411824,36427700084, %T A105996 4313893200131,840463941752366,272080763704257502, %U A105996 147646989859379243894,135364497363933610026002 %N A105996 A050030(2^n+1). %Y A105996 Cf. A107354. %K A105996 nonn %O A105996 0,2 %A A105996 _Max Alekseyev_, May 22 2005 %E A105996 Reference to a dead duplicated sequence changed to an existing one by _Antti Karttunen_, Aug 25 2006