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 1-4 of 4 results.

A287566 Start with 0 and repeatedly substitute 0->0231, 1->2310, 2->3102, 3->1023.

Original entry on oeis.org

0, 2, 3, 1, 3, 1, 0, 2, 1, 0, 2, 3, 2, 3, 1, 0, 1, 0, 2, 3, 2, 3, 1, 0, 0, 2, 3, 1, 3, 1, 0, 2, 2, 3, 1, 0, 0, 2, 3, 1, 3, 1, 0, 2, 1, 0, 2, 3, 3, 1, 0, 2, 1, 0, 2, 3, 2, 3, 1, 0, 0, 2, 3, 1, 2, 3, 1, 0, 0, 2, 3, 1, 3, 1, 0, 2, 1, 0, 2, 3, 3, 1, 0, 2, 1, 0
Offset: 1

Views

Author

Clark Kimberling, May 31 2017

Keywords

Comments

This is the fixed point of the morphism 0->0231, 1->2310, 2->3102, 3->1023 starting with 0. Let t be the (nonperiodic) sequence of positions of 0, and likewise, u for 1, v for 2, and w for 3; then t(n)/n -> 4, u(n)/n -> 4, v(n)/n -> 4, w(n)/n -> 4. Also, t(n) + u(n) + v(n) + w(n) = 16*n - 6 for n >= 1. See A287556 for a guide to related sequences.

Examples

			First three iterations of the morphism:
0231
0231310210232310
0231310210232310102323100231310223100231310210233102102323100231
		

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 2, 3, 1}, 1 -> {2, 3, 2, 0}, 2 -> {3, 1, 0, 2}, 3 -> {1, 0, 2, 3}}] &, {0}, 9];   (* A287566 *)
    Flatten[Position[s, 0]]; (* A287567 *)
    Flatten[Position[s, 1]]; (* A287568 *)
    Flatten[Position[s, 2]]; (* A287569 *)
    Flatten[Position[s, 3]]; (* A287570 *)
    Flatten[SubstitutionSystem[{0->{0,2,3,1},1->{2,3,1,0},2->{3,1,0,2},3->{1,0,2,3}},{0},{4}]] (* Harvey P. Dale, Jul 20 2023 *)

Formula

a(n) = 4n - A287568(n) for n >= 1.

A287567 Positions of 0 in A287566.

Original entry on oeis.org

1, 7, 10, 16, 18, 24, 25, 31, 36, 37, 43, 46, 51, 54, 60, 61, 68, 69, 75, 78, 83, 86, 92, 93, 97, 103, 106, 112, 114, 120, 121, 127, 131, 134, 140, 141, 145, 151, 154, 160, 162, 168, 169, 175, 180, 181, 187, 190, 194, 200, 201, 207, 212, 213, 219, 222, 227
Offset: 1

Views

Author

Clark Kimberling, May 31 2017

Keywords

Comments

a(n) - a(n-1) is in {1,2,3,4,5,6,7} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 3, 1, 2, 0, 2, 0, 3, 1, 0, 3, 1, 2, 1, 2, 0, 3, 0, 3, 1, 2, with
0 in positions given by A287568,
1 in positions given by A287569,
2 in positions given by A287570,
3 in positions given by A287567.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 2, 3, 1}, 1 -> {2, 3, 2, 0}, 2 -> {3, 1, 0, 2}, 3 -> {1, 0, 2, 3}}] &, {0}, 9];   (* A287566 *)
    Flatten[Position[s, 0]]; (* A287567 *)
    Flatten[Position[s, 1]]; (* A287568 *)
    Flatten[Position[s, 2]]; (* A287569 *)
    Flatten[Position[s, 3]]; (* A287570 *)

A287570 Positions of 3 in A287566.

Original entry on oeis.org

3, 5, 12, 14, 20, 22, 27, 29, 34, 39, 41, 48, 49, 56, 58, 63, 66, 71, 73, 80, 81, 88, 90, 95, 99, 101, 108, 110, 116, 118, 123, 125, 129, 136, 138, 143, 147, 149, 156, 158, 164, 166, 171, 173, 178, 183, 185, 192, 196, 198, 203, 205, 210, 215, 217, 224, 225
Offset: 1

Views

Author

Clark Kimberling, May 31 2017

Keywords

Comments

a(n) - a(n-1) is in {1,2,3,4,5,6,7} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 1, 3, 0, 2, 0, 2, 1, 3, 2, 1, 3, 0, 3, 0, 2, 1, 2, 1, 3, 0, with
0 in positions given by A287570,
1 in positions given by A287567,
2 in positions given by A287568,
3 in positions given by A287569.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 2, 3, 1}, 1 -> {2, 3, 2, 0}, 2 -> {3, 1, 0, 2}, 3 -> {1, 0, 2, 3}}] &, {0}, 9];   (* A287566 *)
    Flatten[Position[s, 0]]; (* A287567 *)
    Flatten[Position[s, 1]]; (* A287568 *)
    Flatten[Position[s, 2]]; (* A287569 *)
    Flatten[Position[s, 3]]; (* A287570 *)

A287569 Positions of 2 in A287566.

Original entry on oeis.org

2, 8, 11, 13, 19, 21, 26, 32, 33, 38, 44, 47, 52, 55, 57, 62, 65, 70, 76, 79, 84, 87, 89, 94, 98, 104, 107, 109, 115, 117, 122, 128, 132, 135, 137, 142, 146, 152, 155, 157, 163, 165, 170, 176, 177, 182, 188, 191, 195, 197, 202, 208, 209, 214, 220, 223, 228
Offset: 1

Views

Author

Clark Kimberling, May 31 2017

Keywords

Comments

a(n) - a(n-1) is in {1,2,3,4,5,6,7} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 2, 0, 1, 3, 1, 3, 2, 0, 3, 2, 0, 1, 0, 1, 3, 2, 3, 2, 0, 1, with
0 in positions given by A287569,
1 in positions given by A287570,
2 in positions given by A287567,
3 in positions given by A287568.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0, 2, 3, 1}, 1 -> {2, 3, 2, 0}, 2 -> {3, 1, 0, 2}, 3 -> {1, 0, 2, 3}}] &, {0}, 9];   (* A287566 *)
    Flatten[Position[s, 0]]; (* A287567 *)
    Flatten[Position[s, 1]]; (* A287568 *)
    Flatten[Position[s, 2]]; (* A287569 *)
    Flatten[Position[s, 3]]; (* A287570 *)
Showing 1-4 of 4 results.