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A009611 Expansion of sinh(tan(x)*x). 3
0, 2, 8, 216, 8896, 553120, 48069504, 5564225408, 827281160192, 153537251480064, 34761966006691840, 9422306473314752512, 3010196845995598430208, 1118714469509146379657216, 478278367951534466053799936, 232972682112352062801913282560 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
Vaclav Kotesovec, Graph - asymptotic ratio
FORMULA
a(n) ~ n^(2*n-1/4) * 2^(4*n-3/4) * exp(2*sqrt(2*n)-2*n-1/2) / Pi^(2*n) * (1 - (Pi^2-1)/(12*sqrt(2*n))). - Vaclav Kotesovec, Jan 24 2015
MATHEMATICA
With[{nn=40}, Take[CoefficientList[Series[Sinh[Tan[x]*x], {x, 0, nn}], x] Range[ 0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 23 2014 *)
CROSSREFS
Sequence in context: A012297 A000893 A030177 * A015176 A013345 A013343
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested Mar 15 1997 by Olivier Gérard.
Prior Mathematica program replaced by and more terms from Harvey P. Dale, Jun 23 2014
STATUS
approved

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Last modified June 13 05:35 EDT 2024. Contains 373366 sequences. (Running on oeis4.)