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A012415 Expansion of e.g.f. tanh(arctan(x) * exp(x)). 0
0, 1, 2, -1, -28, -115, 230, 7051, 43080, -172327, -6067382, -47080361, 309697324, 12289126629, 114505019694, -1105109602973, -48948382516592, -522517588252495, 7065091754607762, 338212264324430255 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

EXAMPLE

x + 2/2!*x^2 - 1/3!*x^3 - 28/4!*x^4 - 115/5!*x^5 ...

MATHEMATICA

With[{nn=20}, CoefficientList[Series[Tanh[ArcTan[x]Exp[x]], {x, 0, nn}], x] Range[0, nn]!] * Harvey P. Dale, Dec 13 2018 *)

PROG

(PARI) x = 'x + O('x^30); concat([0], Vec(serlaplace(tanh(atan(x) * exp(x))))) \\ Michel Marcus, Jul 19 2018

CROSSREFS

Sequence in context: A089963 A322230 A012411 * A012660 A015155 A009822

Adjacent sequences:  A012412 A012413 A012414 * A012416 A012417 A012418

KEYWORD

sign

AUTHOR

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

EXTENSIONS

a(0) inserted and title improved by Sean A. Irvine, Jul 18 2018

STATUS

approved

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Last modified July 10 00:05 EDT 2020. Contains 335570 sequences. (Running on oeis4.)