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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A283773 Numbers k such that U(k) = 1 mod 3, where U = A001950 = upper Wythoff sequence.

Original entry on oeis.org

3, 4, 5, 11, 12, 13, 19, 20, 27, 28, 35, 36, 42, 43, 44, 50, 51, 52, 58, 59, 60, 66, 67, 68, 74, 75, 82, 83, 90, 91, 97, 98, 99, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 137, 138, 144, 145, 146, 152, 153, 154, 160, 161, 162, 168, 169, 170, 176
Offset: 1

Views

Author

Clark Kimberling, Mar 18 2017

Keywords

Comments

The sequences A283772, A283773, A283774 partition the positive integers.

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 350; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 3];
    Flatten[Position[u, 0]]  (* A283772 *)
    Flatten[Position[u, 1]]  (* A283773 *)
    Flatten[Position[u, 2]]  (* A283774 *)
  • PARI
    r = (3 + sqrt(5))/2;
    for(n=1, 351, if(floor(n*r)%3==1, print1(n,", "))) \\ Indranil Ghosh, Mar 19 2017
    
  • Python
    import math
    from sympy import sqrt
    r = (3 + sqrt(5))/2
    [n for n in range(1, 351) if int(math.floor(n*r))%3==1] # Indranil Ghosh, Mar 19 2017

Formula

a(n+1) - a(n) is in {1,6,7} for every n.

A283774 Numbers k such that U(k) == 2 mod 3, where U = A001950 = upper Wythoff sequence.

Original entry on oeis.org

1, 2, 8, 9, 10, 16, 17, 18, 24, 25, 26, 32, 33, 34, 40, 41, 48, 49, 55, 56, 57, 63, 64, 65, 71, 72, 73, 79, 80, 81, 87, 88, 89, 95, 96, 103, 104, 110, 111, 112, 118, 119, 120, 126, 127, 128, 134, 135, 136, 142, 143, 150, 151, 158, 159, 165, 166, 167, 173
Offset: 1

Views

Author

Clark Kimberling, Mar 19 2017

Keywords

Comments

The sequences A283772, A283773, A283774 partition the positive integers.

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 350; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 3];
    Flatten[Position[u, 0]]  (* A283772 *)
    Flatten[Position[u, 1]]  (* A283773 *)
    Flatten[Position[u, 2]]  (* A283774 *)
  • PARI
    r = (3 + sqrt(5))/2;
    for(n=1, 351, if(floor(n*r)%3==2, print1(n, ", "))) \\ Indranil Ghosh, Mar 21 2017
    
  • Python
    import math
    from sympy import sqrt
    r = (3 + sqrt(5))/2
    [n for n in range(1, 351) if int(math.floor(n*r))%3==2] # Indranil Ghosh, Mar 21 2017

Formula

a(n+1) - a(n) is in {1,6,7} for every n.
Showing 1-2 of 2 results.