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 A120793 #2 Mar 31 2012 13:20:12 %S A120793 1,12,72,1728,10368,4608,248832,11943936,214990848,2579890176, %T A120793 15479341056,371504185344,2229025112064,26748301344768,53496602689536, %U A120793 1711891286065152,10271347716390912,369768517790072832 %N A120793 Denominators of partial sums of Catalan numbers scaled by powers of -1/12. %C A120793 Numerators are given under A120792. %F A120793 a(n)=denominator(r(n)), with the rationals r(n):=sum(((-1)^k)*C(k)/12^k,k=0..n) with C(k):=A000108(k) (Catalan numbers). Rationals r(n) are taken in lowest terms. %K A120793 nonn,easy,frac %O A120793 0,2 %A A120793 _Wolfdieter Lang_, Jul 20 2006