A009433 -id:A009433 - cp's OEIS frontend

A009434 Expansion of e.g.f: log(1+x)/cosh(tanh(x)).

0, 1, -1, -1, 0, 69, -225, -1653, 3976, 187401, -965385, -14516745, 61266744, 3032650893, -21187300953, -491788726653, 2947006495920, 166337505847057, -1463633608132017, -46261934493321105, 358635306874354320

Offset: 0

R. H. Hardin

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Cf. A009405 - A009420, A009422 - A009433, A009435 - A009439.

R:=PowerSeriesRing(Rationals(), 30);
[0] cat Coefficients(R!(Laplace( Log(1+x)/Cosh(Tanh(x)) ))); // G. C. Greubel, Sep 06 2023

With[{nn=20},CoefficientList[Series[Log[1+x]/Cosh[Tanh[x]],{x,0,nn}], x] Range[0,nn]!] (* Harvey P. Dale, Jun 19 2013 *)

my(x='x+O('x^30)); concat([0],Vec(serlaplace(log(1+x)/cosh(tanh(x))))) \\ Joerg Arndt, Sep 06 2023

def A009434_list(prec):
    P. = PowerSeriesRing(QQ, prec)
    return P( log(1+x)/cosh(tanh(x)) ).egf_to_ogf().list()
A009434_list(40) # G. C. Greubel, Sep 06 2023

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and prior Mathematica program replaced by Harvey P. Dale, Jun 19 2013

A009432 Expansion of e.g.f. log(1+x)/cosh(sinh(x)).

Original entry on oeis.org

0, 1, -1, -1, 0, 9, -45, 447, -2744, 17553, -171585, 1757535, -19723176, 245370969, -3189613245, 44636677407, -674857335120, 10851333193249, -185485926579489, 3356664148618047, -64009236131219760, 1284480775318317225

Offset: 0

R. H. Hardin

G. C. Greubel, Table of n, a(n) for n = 0..449

Cf. A009405 - A009420, A009422 - A009431, A009433 - A009439.

R:=PowerSeriesRing(Rationals(), 30);
[0] cat Coefficients(R!(Laplace( Log(1+x)/Cosh(Sinh(x)) ))); // G. C. Greubel, Sep 08 2023

With[{m=30}, CoefficientList[Series[Log[1+x]/Cosh[Sinh[x]], {x,0,m}], x]*Range[0, m]!] (* modified by G. C. Greubel, Sep 08 2023 *)

def A009432_list(prec):
    P. = PowerSeriesRing(QQ, prec)
    return P( log(1+x)/cosh(sinh(x)) ).egf_to_ogf().list()
A009432_list(31) # G. C. Greubel, Sep 08 2023

Extended with signs by Olivier Gérard, Mar 15 1997

cp's OEIS Frontend

A009434 Expansion of e.g.f: log(1+x)/cosh(tanh(x)).

Views

Author

Keywords

Links

Crossrefs

Programs

Magma

Mathematica

PARI

SageMath

Extensions