The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A068917 Numerators of coefficients in 1/sin(x) - 1/sinh(x) power series. 9
 1, 31, 73, 8191, 5749691557, 3324754717, 22076500342261, 925118910976041358111, 8089941578146657681, 21194489326041221593005331, 3342730069684120811652882591487741, 4204720064739945338027515648494601 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS G. C. Greubel, Table of n, a(n) for n = 1..125 FORMULA a(3k+1) = (4k+2)!, a(3k+2) = (4k+4)!, a(3k+3) = (4k+5)!/2. EXAMPLE cosec(x) - cosech(x) = x/3 + 31*x^5/7560 + 73*x^9/1710720 + 8191*x^13/18681062400 + ... MATHEMATICA Select[Numerator[CoefficientList[Series[1/Sin[x] - 1/Sinh[x], {x, 0, 500}], x]], # != 0 &] (* G. C. Greubel, Nov 11 2016 *) CROSSREFS Cf. A068918. Sequence in context: A155933 A163428 A130468 * A317053 A009408 A165615 Adjacent sequences: A068914 A068915 A068916 * A068918 A068919 A068920 KEYWORD easy,frac,nonn AUTHOR Benoit Cloitre, Mar 29 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 5 02:30 EST 2022. Contains 358572 sequences. (Running on oeis4.)