OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
FORMULA
E.g.f.: exp(tan(x))/(x+sqrt(1+x^2)). - Vaclav Kotesovec, Nov 01 2013
a(n) ~ -2*cos(Pi*n/2-tanh(1)) * n^(n-1) / exp(n). - Vaclav Kotesovec, Nov 01 2013
MATHEMATICA
CoefficientList[Series[Exp[Tan[x]-ArcSinh[x]], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Nov 01 2013 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved