A013059 tan(sinh(x)+arctan(x))=2*x+15/3!*x^3+457/5!*x^5+29617/7!*x^7...

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

Offset

0,1

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..200

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, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Sep 24 2012 *)

Crossrefs

Sequence in context: A139810 A012943 A363834 * A013098 A365534 A158109

Adjacent sequences: A013056 A013057 A013058 * A013060 A013061 A013062

Keyword

nonn

Author

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

Status

approved