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A013121 Expansion of e.g.f. arctan(tanh(x) + log(x+1)). 0
0, 2, -1, -16, 42, 748, -5130, -80792, 1139880, 15089632, -401063040, -3986514112, 203199458880, 1170901443424, -139120136531376, -67846807312832, 122712218206730880, -762584236008814848 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

EXAMPLE

2*x - 1/2!*x^2 - 16/3!*x^3 + 42/4!*x^4 + 748/5!*x^5 ...

MATHEMATICA

With[{nn=20}, Rest[CoefficientList[Series[ArcTan[Tanh[x]+Log[x+1]], {x, 0, nn}], x] Range[0, nn]!]] (* Harvey P. Dale, Aug 08 2016 *)

CROSSREFS

Sequence in context: A162005 A013125 A012967 * A012963 A013120 A012968

Adjacent sequences:  A013118 A013119 A013120 * A013122 A013123 A013124

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

EXTENSIONS

a(0)=0 inserted and title improved by Sean A. Irvine, Jul 31 2018

STATUS

approved

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Last modified October 20 18:08 EDT 2018. Contains 316401 sequences. (Running on oeis4.)