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.

Showing 1-1 of 1 results.

A083032 Numbers that are congruent to {0, 4, 7, 10} mod 12.

Original entry on oeis.org

0, 4, 7, 10, 12, 16, 19, 22, 24, 28, 31, 34, 36, 40, 43, 46, 48, 52, 55, 58, 60, 64, 67, 70, 72, 76, 79, 82, 84, 88, 91, 94, 96, 100, 103, 106, 108, 112, 115, 118, 120, 124, 127, 130, 132, 136, 139, 142, 144, 148, 151, 154, 156, 160, 163, 166, 168, 172
Offset: 1

Views

Author

James Ingram (j.ingram(AT)t-online.de), Jun 01 2003

Keywords

Comments

Key-numbers of the pitches of a dominant seventh chord on a standard chromatic keyboard, with root = 0.

Crossrefs

Bisections: A016957, A272975.
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): A082977
Chords:
Major chord: A083030
Minor chord: A083031
Dominant seventh chord: this sequence

Programs

  • GAP
    Filtered([0..200],n-> n mod 12=0 or n mod 12=4 or n mod 12=7 or n mod 12=10); # Muniru A Asiru, Sep 22 2018
  • Magma
    [(12*n-9+(-1)^n+(-1)^((n+1) div 2)+(-1)^(-(n+1) div 2))/4: n in [1..100]]; // Wesley Ivan Hurt, May 19 2016
    
  • Maple
    A083032:=n->(12*n-9+(-1)^n+(-1)^((n+1)/2)+(-1)^(-(n+1)/2))/4: seq(A083032(n), n=1..100); # Wesley Ivan Hurt, May 19 2016
  • Mathematica
    Select[Range[0,200], MemberQ[{0,4,7,10}, Mod[#,12]]&] (* Harvey P. Dale, Sep 13 2011 *)
    LinearRecurrence[{1,0,0,1,-1},{0,4,7,10,12},100] (* G. C. Greubel, Jun 01 2016 *)
  • PARI
    my(x='x+O('x^99)); concat(0, Vec(x^2*(4+3*x+3*x^2+2*x^3)/((1+x)*(1+x^2)*(1-x)^2))) \\ Altug Alkan, Sep 21 2018
    

Formula

G.f.: x^2*(4 + 3*x + 3*x^2 + 2*x^3)/((1 + x)*(1 + x^2)*(1 - x)^2). - R. J. Mathar, Oct 08 2011
From Wesley Ivan Hurt, May 19 2016: (Start)
a(n) = a(n-1) + a(n-4) - a(n-5) for n > 5.
a(n) = (12*n - 9 + (-1)^n + (-1)^((n+1)/2) + (-1)^(-(n+1)/2))/4. (End)
a(2k) = A016957(k-1) for k > 0, a(2k-1) = A272975(k). - Wesley Ivan Hurt, Jun 01 2016
E.g.f.: (4 - sin(x) + (6*x - 5)*sinh(x) + (6*x - 4)*cosh(x))/2. - Ilya Gutkovskiy, Jun 01 2016
From Jianing Song, Sep 22 2018: (Start)
a(n) = (12*n - 9 + (-1)^n - 2*sin(n*Pi/2))/4.
a(n) = a(n-4) + 12 for n > 4. (End)
Sum_{n>=2} (-1)^n/a(n) = log(3)/8 - log(2)/12 + sqrt(3)*log(sqrt(3)+2)/12 - (5*sqrt(3)-6)*Pi/72. - Amiram Eldar, Dec 31 2021
Showing 1-1 of 1 results.