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 A176493 #5 Mar 30 2012 18:52:05 %S A176493 1,1,4,6,144,240,8640,15120,403200,725760,43545600,79833600, %T A176493 201180672000,373621248000,2092278988800,3923023104000, %U A176493 1883051089920000,3556874280960000,2688996956405760000,5109094217170944000,1605715325396582400000,3065456530302566400000 %N A176493 A091137(n)/(n+1). %F A176493 a(n) = A174727(n)/A027760(n+1). %K A176493 nonn %O A176493 0,3 %A A176493 _Paul Curtz_, Apr 19 2010