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.

A284394 {101->2}-transform of the infinite Fibonacci word A003849.

Original entry on oeis.org

0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0, 1
Offset: 1

Views

Author

Clark Kimberling, May 02 2017

Keywords

Comments

The sequences p = A032766, q = A284395, r = A284396, of positions of 0,1,2, respectively, partition the positive integers. Let t,u,v be the slopes of p, q, r, respectively. Then t = 3/2, u = (9+3*sqrt(5))/2, v = (3+3*sqrt(5))/2, and 1/t + 1/u + 1/v = 1.

Examples

			As a word, A003849 = 01001010010010100..., and replacing each 101 by 2 gives 01002001002002001...
		

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {0}}] &, {0}, 13]  (* A003849 *)
    w = StringJoin[Map[ToString, s]]; w1 = StringReplace[w, {"101" -> "2"}]
    st = ToCharacterCode[w1] - 48 (* A284394 *)
    Flatten[Position[st, 0]]  (* A032766 *)
    Flatten[Position[st, 1]]  (* A284395 *)
    Flatten[Position[st, 2]]  (* A284396 *)