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A012094
E.g.f.: tanh(arcsin(arctan(x))), odd powers only.
1
1, -3, 49, -1859, 127297, -13662371, 2114110257, -445110767139, 122308548673025, -42491524107649475, 18204849127687565745, -9427087716053634833795, 5803356448065850202170945, -4188507975000626549209008995, 3502566426777342320289454951345
OFFSET
0,2
LINKS
EXAMPLE
tanh(arcsin(arctan(x))) = x-3/3!*x^3+49/5!*x^5-1859/7!*x^7+127297/9!*x^9...
MAPLE
a:= n-> (t-> t!*coeff(series(tanh(arcsin(arctan(x))), x, t+1), x, t))(2*n+1):
seq(a(n), n=0..17); # Alois P. Heinz, Feb 15 2018
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tanh[ArcSin[ArcTan[x]]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, May 09 2012 *)
CROSSREFS
Sequence in context: A300990 A062961 A012206 * A012059 A012166 A012068
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved