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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 Table of n, a(n) for n=0..22. 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 Adjacent sequences: A013333 A013334 A013335 * A013337 A013338 A013339 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.)