A012637 tan(arcsinh(x)*cos(x))=x-2/3!*x^3-40/5!*x^5+824/7!*x^7+34880/9!*x^9...

1, -2, -40, 824, 34880, -3510784, -105236352, 50170105088, -740139765760, -1822790066204672, 239991990818783232, 116554901577925656576, -41369324496338787860480, -15006195846954859719360512

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Formula

a(n) ~ (-1)^n * cosh(1) * 2^(2*n+2) * n^(2*n) / ((cosh(Pi*cosh(1))+1) * exp(2*n)). - Vaclav Kotesovec, Nov 01 2013

Mathematica

Table[n!*SeriesCoefficient[Tan[ArcSinh[x]*Cos[x]], {x, 0, n}], {n, 1, 41, 2}] (* Vaclav Kotesovec, Nov 01 2013 *)
With[{nn=30}, Take[CoefficientList[Series[Tan[ArcSinh[x]Cos[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Sep 05 2015 *)

Crossrefs

Sequence in context: A279214 A264716 A264713 * A127429 A322179 A012834

Adjacent sequences: A012634 A012635 A012636 * A012638 A012639 A012640

Keyword

sign

Author

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

Status

approved