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 A121404 #6 Mar 30 2012 16:50:30 %S A121404 0,2,6,12,36,96,342,22266,79806,187122,347976,2171616,4219797672, %T A121404 98059918332 %N A121404 A093483(n)-2. %K A121404 nonn %O A121404 1,2 %A A121404 _N. J. A. Sloane_, Apr 21 2007