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 A203586 #7 Jan 14 2013 03:52:54
%S A203586 13,500,40426,5709600,1256804900,399383584000,173474742285000,
%T A203586 98872482630272000,71645799536067250000,64368175738481971200000,
%U A203586 70249051303937073666500000,91567621291850074309120000000
%N A203586 v(n+1)/v(n), where v=A203585.
%C A203586 See A093883 for a discussion and guide to related sequences.
%t A203586 f[j_] := j + 1; z = 12;
%t A203586 v[n_] := Product[Product[f[j]^2 + f[k]^2, {j, 1, k - 1}], {k, 2, n}]
%t A203586 Table[v[n], {n, 1, z}] (* A203585 *)
%t A203586 Table[v[n + 1]/v[n], {n, 1, z}] (* A203586 *)
%K A203586 nonn
%O A203586 1,1
%A A203586 _Clark Kimberling_, Jan 04 2012