A009301 E.g.f. exp(x/cosh(x)).

1, 1, 1, -2, -11, -4, 181, 624, -3863, -37808, 66121, 2529440, 4478365, -197245632, -1211701763, 17275207936, 226423491793, -1517532372736, -43068302925551, 78275049887232, 8876725117679941, 24598365340871680, -1997577117130009403, -16151599386896207872, 483811389670392875449

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Crossrefs

Cf. A009118, A009562.

Programs

Mathematica

With[{nn=30},CoefficientList[Series[Exp[x/Cosh[x]],{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Jan 26 2016 *)

PARI

N=33;  x='x+O('x^N);
egf=exp(x*1/cosh(x));
Vec(serlaplace(egf))
/* Joerg Arndt, Sep 15 2012 */

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997