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, 3, 59, 871, 325249, 35797, 24362249, 342232522657, 8224154352439, 23157229065769, 9926476934520521, 37638416003805990839, 296699416391356495667713, 691054566545631371393

Offset: 0

Author

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

Keywords

• nonn
• frac

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

Programs

Mathematica

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

Extensions

Name edited by R. J. Mathar, Dec 19 2011