A012951 tan(tan(x)+arcsin(x))=2*x+19/3!*x^3+777/5!*x^5+68913/7!*x^7...

2, 19, 777, 68913, 10552545, 2473498553, 822718602721, 368440852318193, 213728212488651073, 155891727584133609833, 139640409724657756366273, 150696011591407998679347809, 192838464530919232345949380513

Offset

0,1

Links

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

Formula

a(n) ~ 2 * (2*n+1)! / ((1/sqrt(1-r^2) + 1/cos(r)^2) * r^(2*n+2)), where r = 0.6847459895634158528826803233486350363469025628718894198... is the root of the equation tan(r) + arcsin(r) = Pi/2. - Vaclav Kotesovec, Feb 07 2015

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tan[Tan[x]+ArcSin[x]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Sep 16 2012 *)

Crossrefs

Sequence in context: A062623 A155956 A013047 * A012980 A323280 A013110

Adjacent sequences: A012948 A012949 A012950 * A012952 A012953 A012954

Keyword

nonn

Author

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

Status

approved