This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A013551 Numerator of [x^n] in the Taylor expansion exp(cot(x)-coth(x))= 1-2*x/3 +2x^2/9 -4*x^3/81 +2*x^4/243 -136*x^5/25515 +676*x^6/229635 -... 1
 1, -2, 2, -4, 2, -136, 676, -656, 62, -47672, 2714132, -3091664, 7223932, -16788784, 120994136, -15764283616, 13831453742, -3729134588968, 463898158095404, -119174509180016 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The inner function is cot(x)-coth(x) = -2x/3 -4x^5/945 -4x^9/93555 -8x^13/18243225 -... LINKS Harvey P. Dale, Table of n, a(n) for n = 0..485 MATHEMATICA Numerator[CoefficientList[Series[Exp[Cot[x]-Coth[x]], {x, 0, 20}], x] ] (* Harvey P. Dale, Feb 16 2014 *) CROSSREFS Sequence in context: A227509 A279094 A129243 * A252040 A084896 A011388 Adjacent sequences:  A013548 A013549 A013550 * A013552 A013553 A013554 KEYWORD sign,frac AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) EXTENSIONS Name edited by R. J. Mathar, Dec 21 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.