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A012156 arctanh(tan(sinh(x)))=x+5/3!*x^3+121/5!*x^5+7069/7!*x^7+763057/9!*x^9... 0
1, 5, 121, 7069, 763057, 132103157, 33527321257, 11731117858573, 5412661283979361, 3184128808387236581, 2326120405922560979929, 2066008261961436163683709, 2192446490036211173903631121 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) ~ (2*n)! / (arcsinh(Pi/4))^(2*n+1). - Vaclav Kotesovec, Feb 05 2015
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[ArcTanh[Tan[Sinh[x]]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 17 2012 *)
CROSSREFS
Sequence in context: A012077 A012046 A012151 * A368854 A290167 A193479
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
More terms from N. J. A. Sloane, Aug 27 2006
STATUS
approved

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Last modified February 23 08:04 EST 2024. Contains 370269 sequences. (Running on oeis4.)