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 A368064 #4 Dec 10 2023 09:25:33 %S A368064 1,6,24336,870746557824,1311726482483997806493696, %T A368064 256433546267136937832915286844640487014400, %U A368064 15678550451426175377500759401206644047210595564950427820202393600 %N A368064 a(n) = Product_{i=1..n, j=1..n} (i^2 + 4*i*j + j^2). %F A368064 a(n) ~ 2^((3+sqrt(3))*n*(n+1) + (sqrt(3)-1)/6) * 3^(3*n*(n+1) + 13/24) * n^(2*n^2 - 7/6) / (Gamma(1/3)^(1/2) * Gamma(1/4)^(1/3) * Pi^(7/12) * (1 + sqrt(3))^((6*n*(n+1) + 1)/sqrt(3) - 1/2) * exp(3*n^2)). %t A368064 Table[Product[i^2 + 4*i*j + j^2, {i, 1, n}, {j, 1, n}], {n, 0, 7}] %Y A368064 Cf. A367543, A324403, A367542, A079478^2, A368067, A368065, A368066. %K A368064 nonn %O A368064 0,2 %A A368064 _Vaclav Kotesovec_, Dec 10 2023