login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A012162 tan(tan(arcsinh(x)))=x+3/3!*x^3+41/5!*x^5+1187/7!*x^7+62129/9!*x^9... 1
1, 3, 41, 1187, 62129, 4782467, 547167193, 80119022947, 16118331113441, 3804780451118851, 1198259782941477641, 411098266056364045603, 189240360206280390564241, 87405020278156979563746947 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Note that a(25) is negative. - Vaclav Kotesovec, Feb 06 2015

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..190

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tan[Tan[ArcSinh[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Oct 21 2014 *)

CROSSREFS

Sequence in context: A241704 A181675 A012053 * A012225 A012129 A012035

Adjacent sequences:  A012159 A012160 A012161 * A012163 A012164 A012165

KEYWORD

sign

AUTHOR

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

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 17 00:35 EDT 2021. Contains 348048 sequences. (Running on oeis4.)