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A013422
E.g.f.: arcsin(arcsin(x)-tanh(x)) (odd coefficients only).
1
0, 3, -7, 497, 10649, 955757, 167741741, 20817188849, 5637483533393, 1653225944489237, 560689820639903957, 269465649695982142009, 138258119776900090716601, 87774869737967098700912797, 65239835100565334768577561149, 54460490625029012562328972397057
OFFSET
0,2
LINKS
FORMULA
a(n) = (2n+1) * [x^(2n+1)] arcsin(arcsin(x)-tanh(x)).
EXAMPLE
arcsin(arcsin(x)-tanh(x)) = 3/3!*x^3-7/5!*x^5+497/7!*x^7+10649/9!*x^9... .
MAPLE
egf:= arcsin(arcsin(x)-tanh(x)):
a:= n-> (2*n+1)!*coeff(series(egf, x, 2*n+3), x, (2*n+1)):
seq(a(n), n=0..20); # Alois P. Heinz, Mar 06 2013
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[ArcSin[ArcSin[x]-Tanh[x]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 06 2013 *)
CROSSREFS
Sequence in context: A281889 A086559 A013426 * A013424 A013423 A199365
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
More terms from Harvey P. Dale, Mar 06 2013
STATUS
approved