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 A324565 #5 Mar 08 2019 03:01:50
%S A324565 2,16,5184,3292047360,431257150704844800000,
%T A324565 1660988174371634812975670031600844800000,
%U A324565 29842277901990912803108442836098281105491323166448779304684748800000
%N A324565 a(n) = Product_{i=0..n, j=0..n} (C(i)+C(j)), where C(k) = Catalan(k) = A000108(k).
%F A324565 a(n) ~ c * d^n * 2^(4*n^3/3 + 3*n^2) * exp(3*n^2/4) / (Pi^(n^2/2) * n^(3*n^2/2 + 3*n - alfa)), where
%F A324565 d = 1.755243767008515125359629831741161625491476427596217377285488419728083846...
%F A324565 alfa = 0.033913207252709141540468528132950860454628430850651543265936300855299...
%F A324565 c = 1.31959917222402005903928675604752142566298009509...
%t A324565 Table[Product[CatalanNumber[i] + CatalanNumber[j], {i, 0, n}, {j, 0, n}], {n, 0, 7}]
%Y A324565 Cf. A000108, A003046, A324566.
%K A324565 nonn
%O A324565 0,1
%A A324565 _Vaclav Kotesovec_, Mar 07 2019