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 A081137 #3 May 11 2007 03:00:00 %S A081137 0,0,1,21,294,3430,36015,352947,3294172,29647548,259416045,2219448385 %N A081137 Duplicate of A027474. %K A081137 dead %O A081137 0,4