This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A071832 Frequency ratios for notes of C-major scale starting at c = 1 (denominators). 7
 1, 8, 4, 3, 2, 3, 8, 1, 4, 2, 3, 1, 3, 4, 1, 2, 1, 3, 1, 3, 2, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,1). FORMULA a(n+7) = a(n) for n >= 21; (1,1,1,3,1,3,1 repeats). - Rick L. Shepherd, Apr 06 2006 G.f.: (x^27 +x^22 +2*x^20 +x^16 +2*x^15 +4*x^13 +x^11 +2*x^9 +4*x^8 -8*x^6 -3*x^5 -2*x^4 -3*x^3 -4*x^2 -8*x -1) / ((x -1)*(x^6 +x^5 +x^4 +x^3 +x^2 +x +1)). - Colin Barker, Feb 14 2014 EXAMPLE The ratios are 1 (c), 9/8 (d), 5/4 (e), 4/3 (f), 3/2 (g), 5/3 (a), 15/8 (b); followed by these 7 numbers multiplied by successive powers of 2. MATHEMATICA Denominator[2^Floor[#/7]Rationalize[2^((-1+Floor[12(1+Mod[#, 7])/7])/12), 2^-6]]&/@Range[0, 70] (* Federico Provvedi, Feb 14 2014 *) PROG (PARI) r=[1, 9/8, 5/4, 4/3, 3/2, 5/3, 15/8]; for(n=0, 20, a=2^n*r; for(m=1, 7, print1(denominator(a[m]), ", "))) \\ Rick L. Shepherd, Apr 06 2006 (PARI) A071832(n)=denominator([1, 9/8, 5/4, 4/3, 3/2, 5/3, 15/8][n%7+1]*2^(n\7))  \\ M. F. Hasler, Jun 13 2012 CROSSREFS Cf. A071831, A071833. Sequence in context: A050135 A109595 A256782 * A327121 A091475 A197482 Adjacent sequences:  A071829 A071830 A071831 * A071833 A071834 A071835 KEYWORD nonn,frac,easy,nice AUTHOR N. J. A. Sloane, Jun 10 2002 EXTENSIONS More terms from Rick L. Shepherd, Apr 06 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 14 00:32 EDT 2019. Contains 327991 sequences. (Running on oeis4.)