A270598 - OEIS

%I #6 Mar 20 2016 11:36:56

%S 1,1,1,3,14,70,364,2548,21104,189936,1830968,20140648,241712272,

%T 3142259536,43472528384,652087925760,10396900456448,176747307759616,

%U 3162885135453952,60094817573625088,1198006583353972736,25158138250433427456,551506339507727783936

%N E.g.f.: Product_{k>0} (1 + tanh(x^k/k)).

%H Vaclav Kotesovec, <a href="/A270598/b270598.txt">Table of n, a(n) for n = 0..448</a>

%F E.g.f.: Product_{k>0} exp(x^k/k)/cosh(x^k/k).

%F a(n) ~ c * n!, where c = 1/A249673 = 1/Product_{k>=1} cosh(1/k) = 0.472485841489...

%t nn=25; Range[0, nn]! * CoefficientList[Series[Product[1+Tanh[x^k/k], {k, 1, nn}], {x, 0, nn}], x]

%Y Cf. A130263, A130268, A218504, A270597.

%K nonn

%O 0,4

%A _Vaclav Kotesovec_, Mar 20 2016