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 1-3 of 3 results.

A283766 Numbers k such that L(k) is odd, where L = A000201 = lower Wythoff sequence.

Original entry on oeis.org

1, 2, 6, 7, 11, 12, 13, 16, 17, 18, 21, 22, 23, 27, 28, 32, 33, 34, 37, 38, 39, 42, 43, 44, 48, 49, 53, 54, 58, 59, 60, 63, 64, 65, 69, 70, 74, 75, 79, 80, 81, 84, 85, 86, 90, 91, 95, 96, 100, 101, 102, 105, 106, 107, 110, 111, 112, 116, 117, 121, 122, 123
Offset: 1

Views

Author

Clark Kimberling, Mar 17 2017

Keywords

Comments

Complement of A283765.

Crossrefs

Cf. A085002 (characteristic function), A085003 (a left inverse).

Programs

  • Mathematica
    r = GoldenRatio; z = 250; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 2];
    Flatten[Position[u, 0]]  (* A283765 *)
    Flatten[Position[u, 1]]  (* A283766 *)

Formula

a(n+1) - a(n) is in {1,3,4} for every n.
A085003(a(n)) = n for all n >= 1. - Antti Karttunen, Mar 17 2017

A283767 Numbers k such that U(k) is even, where U = A001950 = upper Wythoff sequence.

Original entry on oeis.org

1, 4, 7, 8, 10, 11, 13, 14, 17, 20, 21, 23, 24, 26, 27, 30, 33, 36, 37, 39, 40, 43, 46, 49, 50, 52, 53, 56, 59, 62, 63, 65, 66, 68, 69, 72, 75, 76, 78, 79, 81, 82, 85, 88, 91, 92, 94, 95, 98, 101, 104, 105, 107, 108, 111, 114, 117, 118, 120, 121, 123, 124
Offset: 1

Views

Author

Clark Kimberling, Mar 17 2017

Keywords

Comments

Complement of A283768.

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 250; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 2];
    Flatten[Position[u, 0]]  (* A283767 *)
    Flatten[Position[u, 1]]  (* A283768 *)

Formula

a(n+1) - a(n) is in {1,2,3} for every n.

A283768 Numbers k such that U(k) is odd, where U = A001950 = upper Wythoff sequence.

Original entry on oeis.org

2, 3, 5, 6, 9, 12, 15, 16, 18, 19, 22, 25, 28, 29, 31, 32, 34, 35, 38, 41, 42, 44, 45, 47, 48, 51, 54, 55, 57, 58, 60, 61, 64, 67, 70, 71, 73, 74, 77, 80, 83, 84, 86, 87, 89, 90, 93, 96, 97, 99, 100, 102, 103, 106, 109, 110, 112, 113, 115, 116, 119, 122, 125
Offset: 1

Views

Author

Clark Kimberling, Mar 17 2017

Keywords

Comments

Complement of A283767.

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 250; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 2];
    Flatten[Position[u, 0]]  (* A283767 *)
    Flatten[Position[u, 1]]  (* A283768 *)

Formula

a(n+1) - a(n) is in {1,2,3} for every n.
Showing 1-3 of 3 results.