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 A336636 #5 Jul 28 2020 22:20:41
%S A336636 1,3,33,660,20817,935388,56149098,4311694467,410200118577,
%T A336636 47174279349540,6431874002292978,1023398757621960327,
%U A336636 187566773426941146498,39164789611542644630415,9229712819952662426436507,2435069724188535096598261305
%N A336636 Sum_{n>=0} a(n) * x^n / (n!)^2 = exp(BesselI(0,2*sqrt(x))^3 - 1).
%F A336636 a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} binomial(n,k)^2 * A002893(k) * k * a(n-k).
%t A336636 nmax = 15; CoefficientList[Series[Exp[BesselI[0, 2 Sqrt[x]]^3 - 1], {x, 0, nmax}], x] Range[0, nmax]!^2
%t A336636 a[0] = 1; a[n_] := a[n] = (1/n) Sum[Binomial[n, k]^2 HypergeometricPFQ[{1/2, -k, -k}, {1, 1}, 4] k a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 15}]
%Y A336636 Cf. A002893, A023998, A247452, A336635, A336637.
%K A336636 nonn
%O A336636 0,2
%A A336636 _Ilya Gutkovskiy_, Jul 28 2020