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 A052398 #6 May 11 2007 03:00:00 %S A052398 1,2,6,24,120,719,5003,39429,344837,3291590,33835114,370531683 %N A052398 Duplicate of A047890. %K A052398 dead %O A052398 0,2