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 A012130 arctanh(arcsin(tanh(x)))=x+1/3!*x^3+9/5!*x^5+169/7!*x^7+6513/9!*x^9... 0
 1, 1, 9, 169, 6513, 382449, 33949369, 4083320409, 654225568353, 132856897394785, 33620948951783145, 10322993203249787529, 3791611637554126839505, 1638719968206448148183889 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..13. FORMULA a(n) ~ (2*n)! / (arctanh(sin(1)))^(2*n+1). - Vaclav Kotesovec, Feb 05 2015 MATHEMATICA nn = 20; Table[(CoefficientList[Series[ArcTanh[ArcSin[Tanh[x]]], {x, 0, 2*nn+1}], x] * Range[0, 2*nn+1]!)[[n]], {n, 2, 2*nn, 2}] (* Vaclav Kotesovec, Feb 05 2015 *) CROSSREFS Sequence in context: A052774 A276960 A122725 * A151997 A119032 A215554 Adjacent sequences: A012127 A012128 A012129 * A012131 A012132 A012133 KEYWORD nonn AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) STATUS approved

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Last modified December 7 09:30 EST 2023. Contains 367645 sequences. (Running on oeis4.)