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 A336665 #10 May 04 2024 10:19:03
%S A336665 1,1,10,255,12196,939155,106161756,16554165495,3404986723720,
%T A336665 893137635015219,290965846152033460,115256679181251696803,
%U A336665 54552992572663333862400,30406695393635479756804525,19712738332895648545008815416,14707436666152282009334357074335
%N A336665 a(n) = (n!)^2 * [x^n] 1 / BesselJ(0,2*sqrt(x))^n.
%H A336665 Alois P. Heinz, <a href="/A336665/b336665.txt">Table of n, a(n) for n = 0..99</a>
%F A336665 a(n) ~ c * d^n * n!^2 / sqrt(n), where d = 3.431031961004073074179854315227049823720211... and c = 0.31156343453490677011135864540173577785263... - _Vaclav Kotesovec_, May 04 2024
%t A336665 Table[(n!)^2 SeriesCoefficient[1/BesselJ[0, 2 Sqrt[x]]^n, {x, 0, n}], {n, 0, 15}]
%t A336665 A287316[n_, k_] := A287316[n, k] = If[n == 0, 1, If[k < 1, 0, Sum[Binomial[n, j]^2 A287316[n - j, k - 1], {j, 0, n}]]]; b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[(-1)^(j + 1) Binomial[n, j]^2 A287316[j, k] b[n - j, k], {j, 1, n}]]; a[n_] := b[n, n]; Table[a[n], {n, 0, 15}]
%Y A336665 Cf. A000275, A033935, A336271, A336638, A336639.
%Y A336665 Main diagonal of A340986.
%K A336665 nonn
%O A336665 0,3
%A A336665 _Ilya Gutkovskiy_, Jul 29 2020