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 A306729 #30 Nov 20 2023 04:15:07
%S A306729 2,16,5184,9559130112,109045776752640000000000,
%T A306729 27488263744928988967331390258832998400000000000,
%U A306729 1147897050240877062218236820013018349788772091106840426434074807527014400000000000000
%N A306729 a(n) = Product_{i=0..n, j=0..n} (i! + j!).
%F A306729 a(n) ~ c * 2^(n^2/2 + 2*n) * Pi^(n^2/2 + n) * n^(2*n^3/3 + 2*n^2 + 11*n/6 + 5/2) / exp(8*n^3/9 + 2*n^2 + n), where c = A324569 = 62.14398692334529025548974541735...
%F A306729 a(n) = a(n-1) * A323717(n)^2 / (2*n!). - _Vaclav Kotesovec_, Mar 28 2019
%t A306729 Table[Product[i! + j!, {i, 0, n}, {j, 0, n}], {n, 0, 7}]
%t A306729 Clear[a]; a[n_] := a[n] = If[n == 0, 2, a[n-1] * Product[k! + n!, {k, 0, n}]^2 / (2*n!)]; Table[a[n], {n, 0, 7}] (* _Vaclav Kotesovec_, Mar 27 2019 *)
%t A306729 Table[Product[Product[k! + j!, {k, 0, j}], {j, 1, n}]^2 / (2^(n-1) * BarnesG[n + 2]), {n, 0, 7}] (* _Vaclav Kotesovec_, Mar 27 2019 *)
%o A306729 (Python)
%o A306729 from math import prod, factorial as f
%o A306729 def a(n): return prod(f(i)+f(j) for i in range(n) for j in range(n))
%o A306729 print([a(n) for n in range(1, 8)]) # _Michael S. Branicky_, Feb 16 2021
%Y A306729 Cf. A000178, A055462, A079478, A203482, A217757, A323717, A324403, A325052.
%K A306729 nonn
%O A306729 0,1
%A A306729 _Vaclav Kotesovec_, Mar 06 2019