A013548 Numerator of [x^(2n)] of the Taylor series sech(cosec(x)-coth(x))= 1-x^2/72 +221*x^4/31104 +244939*x^6/235146240 +1846213*x^8/13544423424-...

1, -1, 221, -244939, 1846213, -526960582373, 23968139993843, -5189795464140757, 36594801159269740631, -16691319229288614334663751, 11409300606349966887237659743, -198510162914463324156683262269

Offset

0,3

Links

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

Mathematica

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

Crossrefs

Sequence in context: A011816 A048902 A210135 * A300517 A083958 A083959

Adjacent sequences: A013545 A013546 A013547 * A013549 A013550 A013551

Keyword

sign,frac

Author

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

Extensions

Name edited by R. J. Mathar, Dec 21 2011

Status

approved