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 A335638 #23 Oct 04 2020 06:56:16
%S A335638 1,1,1,7,22,190,1170,11646,109520,1289168,16018064,223757840,
%T A335638 3407971488,55709905056,998011344928,18778681069024,385316251841536,
%U A335638 8225863823985664,189755182485906432,4538893733746003968,116147781156885837824,3078530007519830730752,86521073899573883088896
%N A335638 Expansion of e.g.f. Product_{k>0} (1 + tan(x)^k / k).
%H A335638 Vaclav Kotesovec, <a href="/A335638/b335638.txt">Table of n, a(n) for n = 0..430</a>
%F A335638 E.g.f.: exp( Sum_{i>0} Sum_{j>0} (-1)^(i+1)*tan(x)^(i*j)/(i*j^i) ).
%F A335638 Conjecture: a(n) ~ A080130 * 2^(2*n+1) * n! / Pi^(n+1). - _Vaclav Kotesovec_, Oct 04 2020
%t A335638 max = 22; Range[0, max]! * CoefficientList[Series[Product[1 + Tan[x]^k/k, {k, 1, max}], {x, 0, max}], x] (* _Amiram Eldar_, Oct 03 2020 *)
%o A335638 (PARI) N=40; x='x+O('x^N); Vec(serlaplace(prod(k=1, N, 1+tan(x)^k/k)))
%o A335638 (PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(sum(i=1, N, sum(j=1, N\i, (-1)^(i+1)*tan(x)^(i*j)/(i*j^i))))))
%Y A335638 Cf. A000182, A007838, A335630, A335636, A335637, A336046.
%K A335638 nonn
%O A335638 0,4
%A A335638 _Seiichi Manyama_, Oct 03 2020