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 A012166 arctanh(tan(arcsinh(x))) = x+3/3!*x^3+49/5!*x^5+1915/7!*x^7+143905/9!*x^9... 0
 1, 3, 49, 1915, 143905, 17011475, 2994791825, 719040113675, 229441987074625, 92824148885459875, 46824601078366320625, 28633111489683067566875, 20964654070778933185750625, 18047023186844734022903421875 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..13. FORMULA a(n) ~ (2*n)! * 2^(2*n+1) * exp((2*n+1)*Pi/4) / (exp(Pi/2)-1)^(2*n+1). - Vaclav Kotesovec, Oct 30 2013 MATHEMATICA Table[n!*SeriesCoefficient[ArcTanh[Tan[ArcSinh[x]]], {x, 0, n}], {n, 1, 40, 2}] (* Vaclav Kotesovec, Oct 30 2013 *) CROSSREFS Sequence in context: A012206 A012094 A012059 * A012068 A012126 A203513 Adjacent sequences: A012163 A012164 A012165 * A012167 A012168 A012169 KEYWORD nonn AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) STATUS approved

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Last modified December 2 23:17 EST 2023. Contains 367526 sequences. (Running on oeis4.)