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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A013526 Numerator of [x^(2n)] of the Taylor expansion cosh(cosec(x)-cot(x))=1 +x^2/8 +3*x^4/128 +59*x^6/15360 +871*x^8/1474560 +.... 1
1, 1, 3, 59, 871, 325249, 35797, 24362249, 342232522657, 8224154352439, 23157229065769, 9926476934520521, 37638416003805990839, 296699416391356495667713, 691054566545631371393 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The coefficients of the e.g.f. of x/2, cosh(cosec(x)-cot(x)) = 1 + 1*x^2/(2^2*2!) + 9*x^4/(2^4*4!) + 177*x^6/(2^6*6!) + 6097*x^8/(2^8*8!) + ..., are apparently the absolute values of A003711.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..100

MATHEMATICA

Numerator[Take[CoefficientList[Series[Cosh[Csc[x] - Cot[x]], {x, 0, 35}], x], {1, -2, 2}]] (* Vincenzo Librandi, Nov 12 2016 *)

CROSSREFS

Sequence in context: A057175 A142642 A201850 * A062629 A184953 A185153

Adjacent sequences:  A013523 A013524 A013525 * A013527 A013528 A013529

KEYWORD

nonn,frac

AUTHOR

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

EXTENSIONS

Name edited by R. J. Mathar, Dec 19 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 September 26 05:09 EDT 2017. Contains 292502 sequences.