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 A007172 #4 Dec 11 1999 03:00:00 %S A007172 1,1,1,3,7,24,93,434,2110,10957,58713,321576,1792133,10131027, %T A007172 57949430,334970205,1953890318,11489753730,68054102361,405715557048 %N A007172 Erroneous version of A027610. %K A007172 dead %O A007172 1,4