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 A187802 #12 Jan 26 2024 18:46:30
%S A187802 1,1,16,970,146176,44183536,23478931456,20054284098640,
%T A187802 25800626187206656,47592874959658936576,121099500781576410628096,
%U A187802 411996060596290629454466560,1826628916277875316651443879936,10329535274999799577516027932553216,73156530986984637348101331408897703936
%N A187802 E.g.f.: Sum_{n>=0} Product_{k=1..n} tanh(n*k*x).
%C A187802 Compare to the e.g.f. of A002105, the reduced tangent numbers:
%C A187802 Sum_{n>=0} Product_{k=1..n} tanh(k*x).
%H A187802 Vaclav Kotesovec, <a href="/A187802/b187802.txt">Table of n, a(n) for n = 0..140</a>
%F A187802 a(n) ~ c * d^n * (n!)^3 / sqrt(n), where d = 2.67441747301630303932685879..., c = 0.4405132627693901422580367... . - _Vaclav Kotesovec_, Nov 02 2014
%e A187802 E.g.f.: A(x) = 1 + x + 16*x^2/2! + 970*x^3/3! + 146176*x^4/4! +...
%e A187802 where
%e A187802 A(x) = 1 + tanh(x) + tanh(2*1*x)*tanh(2*2*x) + tanh(3*1*x)*tanh(3*2*x)*tanh(3*3*x) + tanh(4*1*x)*tanh(4*2*x)*tanh(4*3*x)*tanh(4*4*x) +...
%t A187802 With[{nn=20},CoefficientList[Series[Sum[Product[Tanh[n*k*x],{k,n}],{n,0,nn}],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Jan 26 2024 *)
%o A187802 (PARI) {a(n)=local(X=x+x*O(x^n), Egf); Egf=sum(m=0, n, prod(k=1, m, tanh(m*k*X))); n!*polcoeff(Egf, n)}
%o A187802 for(n=0, 20, print1(a(n), ", "))
%Y A187802 Cf. A002105.
%K A187802 nonn
%O A187802 0,3
%A A187802 _Paul D. Hanna_, Jan 06 2013