OFFSET
0,2
FORMULA
E.g.f.: (x+sqrt(1+x^2))*exp(tan(x)). - Vaclav Kotesovec, Nov 01 2013
a(n) ~ -2 * n^(n-1) * cos(Pi*n/2-tanh(1)) / exp(n). - Vaclav Kotesovec, Nov 01 2013
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Exp[ArcSinh[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Sep 19 2012 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Definition clarified by Harvey P. Dale, Sep 19 2012
STATUS
approved