A009136 Expansion of e.g.f. cosh(x*log(1+x)).

1, 0, 0, 0, 12, -60, 330, -2100, 17024, -157248, 1604520, -17875440, 216589032, -2838607200, 40020882720, -603994154400, 9715670780160, -165944432465280, 2999458158459840, -57201489673372800, 1147839380364481920

Offset

0,5

Links

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

Formula

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

Mathematica

With[{nn=30}, CoefficientList[Series[Cosh[x*Log[1+x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Nov 03 2011 *)

Prog

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

Crossrefs

Sequence in context: A216491 A114307 A009031 * A053533 A309309 A324946

Adjacent sequences: A009133 A009134 A009135 * A009137 A009138 A009139

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved