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 A128493 #5 Dec 05 2013 10:26:32
%S A128493 1,81,50625,121550625,9845600625,144149438750625,4117052120156600625,
%T A128493 4117052120156600625,343860310127599440800625,
%U A128493 44812219476138886724578250625,44812219476138886724578250625
%N A128493 Denominators of partial sums for a series for (Pi^4)/96.
%C A128493 Numerators are given in A120269.
%C A128493 See the comments and the W. Lang link under A120269.
%F A128493 a(n)=denominator(r(n)) with r(n):=sum(1/(2*k-1)^4,k=1..n).
%t A128493 a[n_] := (Pi^4 - PolyGamma[3, n + 1/2])/96 // Simplify // Denominator; Table[a[n], {n, 1, 11}] (* _Jean-François Alcover_, Dec 05 2013 *)
%K A128493 nonn,frac,easy
%O A128493 1,2
%A A128493 _Wolfdieter Lang_ Apr 04 2007