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 A368067 #3 Dec 10 2023 09:24:05
%S A368067 1,5,12100,188898484500,91554454518735288960000,
%T A368067 4263420404009649597344435073399120000000,
%U A368067 46073465749493255153019723901007197815549903333795840000000000
%N A368067 a(n) = Product_{i=1..n, j=1..n} (i^2 + 3*i*j + j^2).
%F A368067 a(n) ~ 5^(5*n*(n+1)/2 + 1/2) * n^(2*n^2 - 1) / (2 * Pi * exp(3*n^2) * phi^(sqrt(5)*(n*(n+1) + 1/6) - 1/2)), where phi = A001622 is the golden ratio.
%t A368067 Table[Product[i^2 + 3*i*j + j^2, {i, 1, n}, {j, 1, n}], {n, 0, 7}]
%Y A368067 Cf. A367543, A324403, A367542, A079478^2, A368064, A368065, A368066.
%K A368067 nonn
%O A368067 0,2
%A A368067 _Vaclav Kotesovec_, Dec 10 2023