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A009773
Expansion of tanh(log(1+tan(x))).
0
0, 1, -1, 2, -2, -14, 194, -1828, 15688, -130664, 1037864, -7421008, 36772528, 153779536, -9259356016, 209102239712, -3831278863232, 63200892286336, -954398377549696, 12766540334296832, -131022499047886592
OFFSET
0,4
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Tanh[Log[1+Tan[x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Oct 26 2014 *)
CROSSREFS
Sequence in context: A350923 A291376 A273319 * A325912 A365086 A185044
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
Prior Mathematica program replaced by Harvey P. Dale, Oct 26 2014
STATUS
approved