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 A162918 Natural numbers n such that there are s and w satisfying 0 < s < w and 2*s + 5*w = n. 0
 12, 17, 19, 22, 24, 26, 27, 29, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Number of equal microtone intervals dividing a musical octave, so that it is (formally) possible to compose one octave (according to the diatonic scale) of two semi-tone-steps and five whole-tone-steps, each being a multiple of the microtone interval. LINKS Analysis of equal temperament tuning systems (German language) EXAMPLE 12 = 2*1 + 5*2 17 = 2*1 + 5*3 19 = 2*2 + 5*3 22 = 2*1 + 5*4 ... MATHEMATICA Union[2*First[#]+5*Last[#]&/@Subsets[Range[20], {2}]] (* Harvey P. Dale, Mar 28 2012 *) PROG (Other) Haskell expression: filter (\n -> [ (s, w) | s<-[1..n], w<-[(s+1)..n], 2*s+5*w == n ] /= []) [1..] CROSSREFS Sequence in context: A059390 A179243 A064825 * A105018 A154488 A302359 Adjacent sequences:  A162915 A162916 A162917 * A162919 A162920 A162921 KEYWORD nonn AUTHOR Jan Behrens (jbe-oeis(AT)magnetkern.de), Jul 17 2009 STATUS approved

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Last modified December 13 09:58 EST 2019. Contains 329968 sequences. (Running on oeis4.)