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 A145634 #4 Mar 31 2012 10:22:14
%S A145634 2,12,20,280,2520,27720,27720,11088,62832,5969040,1989680,137287920,
%T A145634 686439600,882565200,25594390800,1586852229600,1586852229600,
%U A145634 11107965607200,410994727466400,410994727466400,16850783826122400
%N A145634 Denominator of the polynomial A_l(x) = sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=13.
%C A145634 For numerators see A145633. For general properties of A_l(x) see A145609.
%t A145634 m = 13; aa = {}; Do[k = 0; Do[k = k + m^(2 r + 1 - d)/d, {d, 1, 2 r}]; AppendTo[aa, Denominator[k]], {r, 1, 30}]; aa (*Artur Jasinski*)
%Y A145634 Cf. A145609 - A145640.
%K A145634 frac,nonn
%O A145634 1,1
%A A145634 _Artur Jasinski_, Oct 14 2008
%E A145634 Edited by _R. J. Mathar_, Aug 21 2009