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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
OFFSET
0,3
LINKS
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: A353913 A012411 A012415 * A015155 A009822 A246909
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