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 A203590 #10 Sep 08 2023 04:03:49
%S A203590 10,884,214600,101696400,79516330400,92782304200000,
%T A203590 151115361757776000,327547876406050976000,911669878205463707200000,
%U A203590 3169019350028190185654400000,13454908637914924371884576000000
%N A203590 v(n+1)/v(n), where v=A203589.
%C A203590 See A093883 for a discussion and guide to related sequences.
%F A203590 a(n) ~ 2^(3*n) * n^(2*n) / exp((2 - Pi/2)*n - Pi/4). - _Vaclav Kotesovec_, Sep 08 2023
%t A203590 f[j_] := 2 j - 1; z = 12;
%t A203590 v[n_] := Product[Product[f[j]^2 + f[k]^2, {j, 1, k - 1}], {k, 2, n}]
%t A203590 Table[v[n], {n, 1, z}] (* A203589 *)
%t A203590 Table[v[n + 1]/v[n], {n, 1, z}] (* A203590 *)
%t A203590 Table[Product[(2*k - 1)^2 + (2*n + 1)^2, {k, 1, n}], {n, 1, 15}] (* _Vaclav Kotesovec_, Sep 08 2023 *)
%K A203590 nonn
%O A203590 1,1
%A A203590 _Clark Kimberling_, Jan 04 2012