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A012660 Expansion of e.g.f. arctan(tanh(x) * exp(x)). 1
0, 1, 2, -1, -28, -115, 422, 10859, 62792, -658855, -17714998, -105832681, 2697504812, 73345212005, 348796937582, -22580196404221, -608734768217968, -1123101121107535, 335099557538486162, 8749237741065576239, -28959745091935025548, -8005533865658264577475 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

EXAMPLE

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

MAPLE

seq(coeff(series(factorial(n)*arctan(tanh(x)*exp(x)), x, n+1), x, n), n=0..25); # Muniru A Asiru, Jul 24 2018

MATHEMATICA

With[{nn=25}, Drop[CoefficientList[Series[ArcTan[Tanh[x] Exp[x]], {x, 0, nn}], x] Range[0, nn]!]] (* Vincenzo Librandi, Jul 24 2018 *)

CROSSREFS

Sequence in context: A322230 A012411 A012415 * A015155 A009822 A246909

Adjacent sequences:  A012657 A012658 A012659 * A012661 A012662 A012663

KEYWORD

sign

AUTHOR

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

EXTENSIONS

a(0) inserted and title improved by Sean A. Irvine, Jul 23 2018

STATUS

approved

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Last modified July 9 14:56 EDT 2020. Contains 335543 sequences. (Running on oeis4.)