

A013059


tan(sinh(x)+arctan(x))=2*x+15/3!*x^3+457/5!*x^5+29617/7!*x^7...


1



2, 15, 457, 29617, 3297169, 560934297, 135342237097, 43959449406097, 18493589269412513, 9782445742655891369, 6354726795266610690553, 4973333104842494619682401, 4615289488773714133654687793
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OFFSET

0,1


LINKS



FORMULA

a(n) ~ 2 * (2*n+1)! / ((1/(1+r^2) + cosh(r)) * r^(2*n+2)), where r = 0.8040812330602181259166071748313991650306370183647674874998... is the root of the equation sinh(r) + arctan(r) = Pi/2.  Vaclav Kotesovec, Feb 07 2015


MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tan[Sinh[x]+ArcTan[x]], {x, 0, nn}], x]Range[0, nn1]!, {2, 1, 2}]] (* Harvey P. Dale, Sep 24 2012 *)


CROSSREFS



KEYWORD

nonn


AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)


STATUS

approved



