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 A203585 #7 Jan 14 2013 08:35:01
%S A203585 1,13,6500,262769000,1500305882400000,1885591784499143760000000,
%T A203585 753074404854223679800035840000000000,
%U A203585 130639388303516205847055577677763494400000000000000
%N A203585 Vandermonde sequence using x^2 + y^2 applied to (2,3,...,n+1).
%C A203585 See A093883 for a discussion and guide to related sequences.
%t A203585 f[j_] := j + 1; z = 12;
%t A203585 v[n_] := Product[Product[f[j]^2 + f[k]^2, {j, 1, k - 1}], {k, 2, n}]
%t A203585 Table[v[n], {n, 1, z}] (* A203585 *)
%t A203585 Table[v[n + 1]/v[n], {n, 1, z}] (* A203586 *)
%K A203585 nonn
%O A203585 1,2
%A A203585 _Clark Kimberling_, Jan 04 2012