A012330 tan(arcsin(x)*sin(x))=2/2!*x^2+280/6!*x^6+1344/8!*x^8+770848/10!*x^10...

0, 2, 0, 280, 1344, 770848, 24428800, 11463637120, 1147515615232, 574163022303744, 126865257434619904, 74474679925545302016, 29259293718147520839680, 21004159848539137867063296

Offset

0,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..224

Formula

a(n) ~ c * (2*n)! / n^(3/2), where c = sin(1)/(sqrt(Pi)*(1 + cos(Pi*sin(1)))) = 3.9081600321945... . - Vaclav Kotesovec, Feb 29 2016

Mathematica

nn = 20; Table[(CoefficientList[Series[Tan[ArcSin[x]*Sin[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Feb 06 2015 *)

Crossrefs

Sequence in context: A221750 A284451 A348183 * A012336 A012449 A012446

Adjacent sequences: A012327 A012328 A012329 * A012331 A012332 A012333

Keyword

nonn

Author

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

Extensions

a(0)=0 prepended by Vaclav Kotesovec, Feb 06 2015

Status

approved