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A009197 Expansion of exp(log(1+x)/cosh(x)). 1
1, 1, 0, -3, -6, 35, 135, -476, -6300, 14349, 298515, 254056, -26673042, -26975169, 1931306377, 16803854768, -336040323112, -1435742838615, 20743481564487, 843925791375728, -11354618863953550, -37784454009996005 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..200

FORMULA

a(n) ~ n! * (-1)^n / (GAMMA(-1/cosh(1)) * n^(1+1/cosh(1))). - Vaclav Kotesovec, Jul 02 2015

MATHEMATICA

CoefficientList[Series[Exp[Log[1+x]/Cosh[x]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jul 02 2015 *)

CROSSREFS

Sequence in context: A143046 A246069 A228279 * A205336 A184390 A130317

Adjacent sequences:  A009194 A009195 A009196 * A009198 A009199 A009200

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified February 24 13:13 EST 2021. Contains 341569 sequences. (Running on oeis4.)