A009084 Expansion of e.g.f.: cos(tanh(log(1+x))).

1, 0, -1, 3, -2, -40, 314, -1134, -3044, 87408, -733636, 1835020, 43592176, -792796368, 6272579312, 14019198480, -1257528653744, 20065121039744, -124527163941136, -2075494412476368, 75585686698926496, -1110720454454795520

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..250

Example

cos(tanh(log(1+x))) = 1 +0*x/1! -1*x^2/2! +3*x^3/3! -2*x^4/4! -40*x^5/5! +...

Mathematica

With[{nn=30}, CoefficientList[Series[Cos[Tanh[Log[1+x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Sep 07 2012 *)

Prog

(PARI) x='x+O('x^30); Vec(serlaplace(cos(tanh(log(1+x))))) \\ G. C. Greubel, Jul 24 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cos(Tanh(Log(1+x))))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 24 2018

Crossrefs

Sequence in context: A136635 A062743 A370825 * A096057 A179984 A260888

Adjacent sequences: A009081 A009082 A009083 * A009085 A009086 A009087

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified by Harvey P. Dale, Sep 07 2012

Status

approved