login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A013533 Numerator of [x^(2n+1)] in the Taylor expansion arctan(cosec(x) - cosech(x)). 1
1, -1, 67, -319, 172747, -5036627, 12689179, -142848518639, 9522619510673, -15014600586761717, 98523462918652219853, -281638034717631160979, 20971906033995645898061, -1307646596002305911998781633 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..200

EXAMPLE

x/3 - x^3/81 + 67*x^5/13608 - 319*x^7/612360 + 172747*x^9/1745960832 - ...

MATHEMATICA

Numerator[Take[CoefficientList[Series[ArcTan[Csc[x] - Csch[x]], {x, 0, 25}], x], {2, -1, 2}]] (* G. C. Greubel, Nov 12 2016 *)

CROSSREFS

Cf. A068917.

Sequence in context: A270615 A142804 A033242 * A012865 A026911 A142371

Adjacent sequences:  A013530 A013531 A013532 * A013534 A013535 A013536

KEYWORD

sign,frac

AUTHOR

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

EXTENSIONS

Name edited by R. J. Mathar, Dec 20 2011

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified March 30 14:19 EDT 2017. Contains 284302 sequences.