OFFSET
0,4
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..448
FORMULA
E.g.f.: Product_{k>0} exp(x^k/k)/cosh(x^k/k).
a(n) ~ c * n!, where c = 1/A249673 = 1/Product_{k>=1} cosh(1/k) = 0.472485841489...
MATHEMATICA
nn=25; Range[0, nn]! * CoefficientList[Series[Product[1+Tanh[x^k/k], {k, 1, nn}], {x, 0, nn}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Mar 20 2016
STATUS
approved