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A009713
Expansion of tan(tanh(tan(x))).
0
1, 2, 8, -176, -16384, -969728, -32455680, 4303626240, 1468506210304, 269552004300800, 24649152071991296, -7396863878894714880, -5630959968640999358464, -2114449853843696991076352
OFFSET
0,2
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tan[Tanh[Tan[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Aug 03 2016 *)
CROSSREFS
Sequence in context: A076548 A167009 A350808 * A265597 A213200 A317794
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Prior Mathematica program replaced by Harvey P. Dale, Aug 03 2016
STATUS
approved