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.

A287156 2-limiting word of the morphism 0->10, 1->21, 2->0.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, May 22 2017

Keywords

Comments

Starting with 0, the first 4 iterations of the morphism yield words shown here:
1st: 10
2nd: 2110
3rd: 0212110
4th: 1002010212110
The 2-limiting word is the limit of the words for which the number of iterations is congruent to 2 mod 3.
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}.

Examples

			The 2nd, 5th, and 8th iterates are 2110, 211010021100210212110, 211010021100210212110100210212110021211021101002110021021211002121102110100210212110211010021211010021100210212110.
		

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 11]   (* A287156 *)
    Flatten[Position[s, 0]] (* A287157 *)
    Flatten[Position[s, 1]] (* A287158 *)
    Flatten[Position[s, 2]] (* A287159 *)

A287158 Positions of 1 in A287156.

Original entry on oeis.org

2, 3, 5, 9, 10, 14, 17, 19, 20, 22, 26, 29, 31, 32, 36, 38, 39, 42, 43, 45, 49, 50, 54, 57, 59, 60, 64, 66, 67, 70, 71, 73, 77, 80, 82, 83, 86, 87, 89, 93, 95, 96, 98, 102, 103, 107, 110, 112, 113, 115, 119, 122, 124, 125, 129, 131, 132, 135, 136, 138, 142
Offset: 1

Views

Author

Clark Kimberling, May 22 2017

Keywords

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 11] (* A287156 *)
    Flatten[Position[s, 0]] (* A287157 *)
    Flatten[Position[s, 1]] (* A287158 *)
    Flatten[Position[s, 2]] (* A287159 *)

A287159 Positions of 2 in A287156.

Original entry on oeis.org

1, 8, 13, 16, 18, 25, 28, 30, 35, 37, 41, 48, 53, 56, 58, 63, 65, 69, 76, 79, 81, 85, 92, 94, 101, 106, 109, 111, 118, 121, 123, 128, 130, 134, 141, 144, 146, 150, 157, 159, 166, 171, 174, 176, 181, 183, 187, 194, 196, 203, 208, 211, 213, 217, 224, 229, 232
Offset: 1

Views

Author

Clark Kimberling, May 22 2017

Keywords

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 1}, 2 -> 0}] &, {0}, 11] (* A287156 *)
    Flatten[Position[s, 0]] (* A287157 *)
    Flatten[Position[s, 1]] (* A287158 *)
    Flatten[Position[s, 2]] (* A287159 *)
Showing 1-3 of 3 results.