cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A082977 Numbers that are congruent to {0, 1, 3, 5, 6, 8, 10} mod 12.

Original entry on oeis.org

0, 1, 3, 5, 6, 8, 10, 12, 13, 15, 17, 18, 20, 22, 24, 25, 27, 29, 30, 32, 34, 36, 37, 39, 41, 42, 44, 46, 48, 49, 51, 53, 54, 56, 58, 60, 61, 63, 65, 66, 68, 70, 72, 73, 75, 77, 78, 80, 82, 84, 85, 87, 89, 90, 92, 94, 96, 97, 99, 101, 102, 104, 106, 108, 109, 111
Offset: 1

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Author

N. J. A. Sloane, May 31 2003

Keywords

Comments

James Ingram suggests that this (with the initial 0 omitted) is the correct version of Fludd's sequence, rather than A047329. See also A083026.
Key-numbers of the pitches of a Hypophrygian mode scale on a standard chromatic keyboard, with root = 0. A Hypophrygian mode scale can, for example, be played on consecutive white keys of a standard keyboard, starting on the root tone B. - James Ingram (j.ingram(AT)t-online.de), Jun 01 2003

References

  • Robert Fludd, Utriusque Cosmi ... Historia, Oppenheim, 1617-1619.

Crossrefs

Cf. A047329. Different from A000210.
A guide for some sequences related to modes and chords:
Modes:
Lydian mode (F): A083089
Ionian mode (C): A083026
Mixolydian mode (G): A083120
Dorian mode (D): A083033
Aeolian mode (A): A060107 (raised seventh: A083028)
Phrygian mode (E): A083034
Locrian mode (B): this sequence
Chords:
Major chord: A083030
Minor chord: A083031
Dominant seventh chord: A083032

Programs

  • Haskell
    a082977 n = a082977_list !! (n-1)
    a082977_list = [0, 1, 3, 5, 6, 8, 10] ++ map (+ 12) a082977_list
    -- Reinhard Zumkeller, Jan 07 2014
    
  • Magma
    [n : n in [0..150] | n mod 12 in [0, 1, 3, 5, 6, 8, 10]]; // Wesley Ivan Hurt, Jul 19 2016
    
  • Maple
    A082977:=n->12*floor(n/7)+[0, 1, 3, 5, 6, 8, 10][(n mod 7)+1]: seq(A082977(n), n=0..100); # Wesley Ivan Hurt, Jul 19 2016
  • Mathematica
    CoefficientList[Series[x(1 + x + 2*x^4)(1 + x + x^2)/((1 - x)^2*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)), {x, 0, 100}], x] (* Vincenzo Librandi, Jan 06 2013 *)
    fQ[n_] := MemberQ[{0, 1, 3, 5, 6, 8, 10}, Mod[n, 12]]; Select[ Range[0, 111], fQ] (* Robert G. Wilson v, Jan 07 2014 *)
    LinearRecurrence[{1, 0, 0, 0, 0, 0, 1, -1}, {0, 1, 3, 5, 6, 8, 10, 12}, 70] (* Jianing Song, Sep 22 2018 *)
    Floor@Range[0,2^8,12/7] (* Federico Provvedi, Oct 18 2018 *)
  • PARI
    x='x+O('x^99); concat(0, Vec(x*(1+x+2*x^4)*(1+x+x^2)/((1-x)^2*(1+x+x^2+x^3+x^4+x^5+x^6)))) \\ Jianing Song, Sep 22 2018

Formula

G.f.: x*(1 + x + 2*x^4)*(1 + x + x^2)/((1 - x)^2*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - R. J. Mathar, Sep 17 2008
From Wesley Ivan Hurt, Jul 19 2016: (Start)
a(n) = a(n-1) + a(n-7) - a(n-8) for n > 8.
a(n) = (84*n - 105 - 2*(n mod 7) - 2*((n + 1) mod 7) + 5*((n + 2) mod 7) - 2*((n + 3) mod 7) - 2*((n + 4) mod 7) + 5*((n + 5) mod 7) - 2*((n + 6) mod 7))/49.
a(7k) = 12k - 2, a(7k-1) = 12k - 4, a(7k-2) = 12k - 6, a(7k-3) = 12k - 7, a(7k-4) = 12k - 9, a(7k-5) = 12k - 11, a(7k-6) = 12k - 12. (End)
a(n) = a(n-7) + 12 for n > 7. - Jianing Song, Sep 22 2018
a(n) = floor(12*(n-1)/7). - Federico Provvedi, Oct 18 2018
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