A009156 Expansion of e.g.f.: cosh(tan(log(1+x))).

1, 0, 1, -3, 20, -140, 1216, -12096, 137080, -1737504, 24368656, -374527120, 6259083896, -112992788688, 2191121957480, -45420491782680, 1002232901602496, -23453004823018496, 580102806342112960

Offset

0,4

Links

Table of n, a(n) for n=0..18.

Mathematica

With[{nn=20}, CoefficientList[Series[Cosh[Tan[Log[1+x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Dec 15 2014 *)

Crossrefs

Sequence in context: A082143 A342055 A371411 * A074573 A068571 A074569

Adjacent sequences: A009153 A009154 A009155 * A009157 A009158 A009159

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and prior Mathematica program replaced by Harvey P. Dale, Dec 15 2014

Status

approved