A203590 - OEIS

%I #10 Sep 08 2023 04:03:49

%S 10,884,214600,101696400,79516330400,92782304200000,

%T 151115361757776000,327547876406050976000,911669878205463707200000,

%U 3169019350028190185654400000,13454908637914924371884576000000

%N v(n+1)/v(n), where v=A203589.

%C See A093883 for a discussion and guide to related sequences.

%F a(n) ~ 2^(3*n) * n^(2*n) / exp((2 - Pi/2)*n - Pi/4). - _Vaclav Kotesovec_, Sep 08 2023

%t f[j_] := 2 j - 1; z = 12;

%t v[n_] := Product[Product[f[j]^2 + f[k]^2, {j, 1, k - 1}], {k, 2, n}]

%t Table[v[n], {n, 1, z}]          (* A203589 *)

%t Table[v[n + 1]/v[n], {n, 1, z}] (* A203590 *)

%t Table[Product[(2*k - 1)^2 + (2*n + 1)^2, {k, 1, n}], {n, 1, 15}] (* _Vaclav Kotesovec_, Sep 08 2023 *)

%K nonn

%O 1,1

%A _Clark Kimberling_, Jan 04 2012