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 A203519 #12 Apr 09 2021 03:43:56
%S A203519 3,20,336,12870,1270080,311323584,197399802600,321880885724160,
%T A203519 1365311591573529600,15068868587132753685600,
%U A203519 434169705562891299584593920,32678748925653999616045678080000,6431834564578466234122576826339121600
%N A203519 a(n) = v(n+1)/v(n), where v=A203518.
%F A203519 a(n) ~ c * phi^(n*(n+2) + 5/6) / 5^(n/2 + 1/4), where phi = A001622 = (1+sqrt(5))/2 is the golden ratio and c = 3.990771264633156107481636998828550132941483550455485713064916076346986459357... - _Vaclav Kotesovec_, Apr 09 2021
%t A203519 f[j_] := Fibonacci[j + 1]; z = 15;
%t A203519 v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}]
%t A203519 d[n_] := Product[(i - 1)!, {i, 1, n}] (* A000178(n-1) *)
%t A203519 Table[v[n], {n, 1, z}] (* A203518 *)
%t A203519 Table[v[n + 1]/v[n], {n, 1, z - 1}] (* A203519 *)
%t A203519 Table[v[n]/d[n], {n, 1, 20}] (* A203520 *)
%Y A203519 Cf. A203518, A000045, A093883.
%K A203519 nonn
%O A203519 1,1
%A A203519 _Clark Kimberling_, Jan 03 2012