A009093 - OEIS

A009093

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

1, 0, 0, 0, -12, 60, -90, 420, -8960, 64512, -299880, 3709200, -52709976, 480109344, -4993564576, 83895608160, -1246488056320, 15764924418944, -251656080793536, 4849396180905600, -84861914800295552, 1455466222530055680

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OFFSET

0,5

LINKS

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

MATHEMATICA

With[{nmax = 30}, CoefficientList[Series[Cos[Tanh[x]*Log[1 + x]], {x, 0, nmax}], x]*Range[0, nmax]!] (* G. C. Greubel, Jul 25 2018 *)

PROG

(PARI) x='x+O('x^30); Vec(serlaplace(cos(tanh(x)*log(1+x)))) \\ G. C. Greubel, Jul 25 2018

(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cos(Tanh(x)*Log(1+x)))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 25 2018

CROSSREFS

Sequence in context: A372135 A012658 A012407 * A012400 A009172 A012405

Adjacent sequences: A009090 A009091 A009092 * A009094 A009095 A009096

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved