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 A051905 #3 Jun 01 2010 03:00:00 %S A051905 2,4,12,24,120,120,840,1680,5040,5040,55440,55440,720720,720720,720720 %N A051905 Duplicate of A051426. %K A051905 dead %O A051905 1,1