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 A013064 arctanh(sinh(x)+arctan(x))=2*x+15/3!*x^3+713/5!*x^5+82481/7!*x^7... 0
 2, 15, 713, 82481, 17926289, 6251997081, 3199183099305, 2256926363091921, 2099642392012962209, 2490468291041882743721, 3668423635534285779378041, 6569558349739213693016437665 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS FORMULA a(n) ~ (2*n)! / r^(2*n+1), where r = 0.5079168569437311537765199369846945055215... is the root of the equation sinh(r)+arctan(r) = 1. - Vaclav Kotesovec, Feb 05 2015 MATHEMATICA nn = 20; Table[(CoefficientList[Series[ArcTanh[ArcTan[x] + Sinh[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: A015185 A203467 A071627 * A013095 A208051 A038017 Adjacent sequences: A013061 A013062 A013063 * A013065 A013066 A013067 KEYWORD nonn AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) STATUS approved

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Last modified March 28 08:25 EDT 2023. Contains 361585 sequences. (Running on oeis4.)