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 A203695 #8 Jan 14 2013 08:30:27
%S A203695 1,10,16650,24928779600,111827645954579880000,
%T A203695 3822731887490658669088662984000000,
%U A203695 2132112202139633769017736141415928803125840000000000
%N A203695 Vandermonde sequence using x^2 + y^2 applied to the first n triangular numbers: 1,3,6,10,...,n(n+1)/2.
%C A203695 See A093883 for a discussion and guide to related sequences.
%t A203695 f[j_] := j (j + 1)/2; z = 11;
%t A203695 u[n_] := Product[f[j]^2 + f[k]^2, {j, 1, k - 1}]
%t A203695 v[n_] := Product[u[n], {k, 2, n}]
%t A203695 Table[v[n], {n, 1, z}] (* A203695 *)
%t A203695 Table[v[n + 1]/v[n], {n, 1, z}] (* A203696 *)
%K A203695 nonn
%O A203695 1,2
%A A203695 _Clark Kimberling_, Jan 04 2012