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 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A099030 Number of tone-rows in n-tone music. 2
 1, 3, 8, 38, 192, 1320, 10176, 91296, 908160, 9985920, 119761920, 1556847360, 21794734080, 326920043520, 5230700052480, 88921882828800, 1600593472880640, 30411275613143040, 608225502973132800, 12772735554075033600 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 LINKS Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 08 2006, Table of n, a(n) for n = 3..38 Samuel Herman, Eirini Poimenidou, Orbits of Hamiltonian Paths and Cycles in Complete Graphs, arXiv:1905.04785 [math.CO], 2019. H. Fripertinger, Enumeration in musical theory, Séminaire Lotharingien de Combinatoire, B26a (1991), 14 pp. FORMULA (1/4) [(n-1)!+(n-1)!! ] if n odd, (1/4) [(n-1)!+(n/2+1)(n-2)!! ] if even. MATHEMATICA a[n_] := If[OddQ[n], (n-1)! + (n-1)!!, (n-1)! + (n/2 + 1)*(n-2)!!] / 4; Table[a[n], {n, 3, 38}] (* Jean-François Alcover, Aug 01 2016 *) PROG (PARI) doubfact(n)=if(n<2, 1, n*doubfact(n-2)); for(n=3, 50, if(n%2==1, print1(((n-1)!+doubfact(n-1))/4, ", "), print1(((n-1)!+(n/2+1)*doubfact(n-2))/4, ", "))) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 02 2006 CROSSREFS Apart from initial terms, same as A089066. - Ray Jerome, Feb 25 2005 Sequence in context: A219953 A286075 A089066 * A264657 A190658 A366629 Adjacent sequences: A099027 A099028 A099029 * A099031 A099032 A099033 KEYWORD nonn,easy AUTHOR Ralf Stephan, Sep 27 2004 EXTENSIONS More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 02 2006 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 2 14:19 EST 2023. Contains 367524 sequences. (Running on oeis4.)