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A013184 exp(arctanh(x)+tanh(x)) = 1+2*x+4/2!*x^2+8/3!*x^3+16/4!*x^4+72/5!*x^5... 0
1, 2, 4, 8, 16, 72, 544, 3936, 25344, 193920, 1920384, 21876736, 246359040, 2967878656, 39508168704, 589063146496, 9120978370560, 149737853943808, 2587275558617088, 48291040167362560, 939278027083448320 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) ~ 2*exp(tanh(1)) * n^n/exp(n) = 2*exp((exp(2)-1)/(exp(2)+1)) * n^n/exp(n). - Vaclav Kotesovec, Oct 24 2013

MATHEMATICA

With[{nn=20}, CoefficientList[Series[Exp[ArcTanh[x]+Tanh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jul 24 2011 *)

CROSSREFS

Sequence in context: A322037 A013133 A012997 * A066713 A004000 A051300

Adjacent sequences:  A013181 A013182 A013183 * A013185 A013186 A013187

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified December 1 13:38 EST 2021. Contains 349429 sequences. (Running on oeis4.)