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.

A287066 Start with 1 and repeatedly substitute 0->01, 1->12, 2->0.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, May 20 2017

Keywords

Comments

This is the fixed point of the morphism 0->01, 1->12, 2->0 starting with 1. Let u be the sequence of positions of 0, and likewise, v for 1 and w for 2. Let U, V, W be the limits of u(n)/n, v(n)/n, w(n)/n, respectively. Then 1/U + 1/V + 1/W = 1, where
U = 3.079595623491438786010417...,
V = 2.324717957244746025960908...,
W = U + 1 = 4.079595623491438786010417....
If n >=2, then u(n) - u(n-1) is in {1,2,3,4,6}, v(n) - v(n-1) is in {1,2,3,4}, and w(n) - w(n-1) is in {2,3,4,5,7}. For n >= 1, the number of terms resulting from n iterations of the morphism is A005251(n+2).

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 2}, 2 -> 0}] &, {1}, 10] (* A287066 *)
    Flatten[Position[s, 0]]  (* A287067 *)
    Flatten[Position[s, 1]]  (* A287068 *)
    Flatten[Position[s, 2]]  (* A287069 *)

A287067 Positions of 0 in A287066.

Original entry on oeis.org

3, 4, 6, 10, 16, 17, 23, 26, 27, 29, 35, 38, 39, 43, 44, 46, 50, 56, 59, 60, 64, 65, 67, 73, 74, 76, 80, 86, 87, 93, 96, 97, 101, 102, 104, 110, 111, 113, 117, 123, 126, 127, 129, 133, 139, 140, 146, 149, 150, 152, 158, 161, 162, 166, 167, 169, 175, 176, 178
Offset: 1

Views

Author

Clark Kimberling, May 21 2017

Keywords

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 2}, 2 -> 0}] &, {1}, 10] (* A287066 *)
    Flatten[Position[s, 0]]  (* A287067 *)
    Flatten[Position[s, 1]]  (* A287068 *)
    Flatten[Position[s, 2]]  (* A287069 *)

A287068 Positions of 1 in A287066.

Original entry on oeis.org

1, 5, 7, 8, 11, 12, 14, 18, 19, 21, 24, 28, 30, 31, 33, 36, 40, 41, 45, 47, 48, 51, 52, 54, 57, 61, 62, 66, 68, 69, 71, 75, 77, 78, 81, 82, 84, 88, 89, 91, 94, 98, 99, 103, 105, 106, 108, 112, 114, 115, 118, 119, 121, 124, 128, 130, 131, 134, 135, 137, 141
Offset: 1

Views

Author

Clark Kimberling, May 21 2017

Keywords

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 2}, 2 -> 0}] &, {1}, 10] (* A287066 *)
    Flatten[Position[s, 0]]  (* A287067 *)
    Flatten[Position[s, 1]]  (* A287068 *)
    Flatten[Position[s, 2]]  (* A287069 *)
Showing 1-3 of 3 results.