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 A169971 #1 Aug 27 2010 03:00:00 %S A169971 1,6,8,180,32,10080,3456,453600,115200,47900160,71680,217945728000, %T A169971 36578304000,2241727488000,45984153600,2000741783040000 %N A169971 Erroneous version of A002689. %D A169971 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A169971 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %K A169971 dead %O A169971 0,2