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A012944 E.g.f.: arctanh(tan(x)+sin(x))=2*x+17/3!*x^3+865/5!*x^5+109007/7!*x^7... 0
2, 17, 865, 109007, 25619185, 9676271447, 5360201676505, 4094035686738287, 4123461735603625825, 5295201587012317791527, 8444330016251458512555145, 16372171162004294836053543167 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
a(n) ~ (2*n)! / (arctan((1-sqrt(2) + sqrt(2*sqrt(2)-1)) / (sqrt(2)-1 + sqrt(2*sqrt(2)-1))))^(2*n+1). - Vaclav Kotesovec, Feb 05 2015
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[ArcTanh[Tan[x]+Sin[x]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Jun 26 2012 *)
CROSSREFS
Sequence in context: A268270 A167436 A015189 * A013099 A013060 A012988
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Definition clarified by Harvey P. Dale, Jun 26 2012
STATUS
approved

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Last modified April 25 06:49 EDT 2024. Contains 371964 sequences. (Running on oeis4.)