A009134 Expansion of cosh(log(1+x)*cosh(x)).

1, 0, 1, -3, 24, -120, 870, -6300, 55048, -527688, 5684640, -66667920, 850501608, -11675938560, 171892670040, -2700017534760, 45091783981312, -797817318871552, 14909393380875840, -293452734825051264

Offset

0,4

Links

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

Formula

a(n) ~ (-1)^n * n! * n^(cosh(1)-1) / (2*Gamma(cosh(1))). - Vaclav Kotesovec, Jul 28 2018

Mathematica

With[{nmax = 30}, CoefficientList[Series[Cosh[Log[1 + x]*Cosh[x]], {x, 0, nmax}], x]*Range[0, nmax]!] (* G. C. Greubel, Jul 28 2018 *)

Prog

(PARI) x='x+O('x^30); Vec(serlaplace(cosh(log(1+x)*cosh(x)))) \\ G. C. Greubel, Jul 28 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cosh(Log(1+x)*Cosh(x)))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 28 2018

Crossrefs

Sequence in context: A268633 A324065 A151883 * A009137 A319097 A326789

Adjacent sequences: A009131 A009132 A009133 * A009135 A009136 A009137

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved