login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A012732 cos(arctanh(x)*arctan(x)) = 1-12/4!*x^4-9968/8!*x^8-77575872/12!*x^12... 0
1, -12, -9968, -77575872, -2494079278848, -227607911866125312, -47454799045677121597440, -19613396255307422099013550080, -14538029942147907114791552602275840 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..8.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Cos[ArcTanh[x]*ArcTan[x]], {x, 0, nn}], x] Range[0, nn-2]!, {1, -1, 4}]] (* Ray Chandler, Nov 28 2016 *)

CROSSREFS

Sequence in context: A012532 A343699 A346717 * A001322 A159411 A074983

Adjacent sequences:  A012729 A012730 A012731 * A012733 A012734 A012735

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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 17 00:01 EDT 2022. Contains 356180 sequences. (Running on oeis4.)