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A013336 Expansion of e.g.f.: arctanh(exp(x)-sec(x)). 0
0, 1, 0, 3, -4, 45, -180, 1743, -13704, 135705, -1613160, 18065883, -276222604, 3655783365, -65652672540, 1034667581223, -20865280018704, 387014665823025, -8593188683674320, 184059142857923763, -4464138375366282004, 108277288526211374685, -2858191345505462554500 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
EXAMPLE
x + (3/3!)*x^3 - (4/4!)*x^4 + (45/5!)*x^5 - (180/6!)*x^6 + (1743/7!)*x^7 - ...
MATHEMATICA
With[{nn=20}, CoefficientList[Series[ArcTanh[Exp[x]-Sec[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Oct 11 2014 *)
CROSSREFS
Sequence in context: A041055 A246626 A032838 * A264509 A198051 A032839
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Definition clarified and zero prepended by Harvey P. Dale, Oct 11 2014
Name edited by Michel Marcus, Sep 01 2019
More terms from Petros Hadjicostas, Sep 01 2019
STATUS
approved

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Last modified April 14 17:14 EDT 2024. Contains 371666 sequences. (Running on oeis4.)