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A012324
arctanh(arcsin(x)*exp(x))=x+2/2!*x^2+6/3!*x^3+32/4!*x^4+248/5!*x^5...
0
0, 1, 2, 6, 32, 248, 2240, 24584, 314176, 4604864, 75708928, 1384714496, 27844334080, 610980624512, 14521108083456, 371703786041600, 10193800681881600, 298204898039689216, 9268641663992807424
OFFSET
0,3
FORMULA
a(n) ~ (n-1)! / (2 * r^n), where r = 0.546947494527286418832891321710111770819... is the root of the equation arcsin(r)*exp(r) = 1. - Vaclav Kotesovec, Feb 05 2015
MATHEMATICA
With[{nn=20}, CoefficientList[Series[ArcTanh[ArcSin[x]Exp[x]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Feb 02 2012 *)
CROSSREFS
Sequence in context: A012521 A211195 A346452 * A121676 A326096 A346270
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Prepended missing a(0)=0 from Vaclav Kotesovec, Feb 05 2015
STATUS
approved