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.

A287576 Start with 0 and repeatedly substitute 0->0321, 1->3210, 2->2103, 3->1032.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Jun 01 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:
0321
0321103221033210
0321103221033210321003211032210321033210032110321032210332100321
		

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
    Flatten[Position[s, 0]]; (* A287577 *)
    Flatten[Position[s, 1]]; (* A287578 *)
    Flatten[Position[s, 2]]; (* A287579 *)
    Flatten[Position[s, 3]]; (* A287580 *)

Formula

a(n) = 4n - A287578(n) for n >= 1.

A287577 Positions of 0 in A287576.

Original entry on oeis.org

1, 6, 11, 16, 20, 21, 26, 31, 35, 40, 41, 46, 50, 55, 60, 61, 66, 71, 76, 77, 81, 86, 91, 96, 100, 101, 106, 111, 115, 120, 121, 126, 131, 136, 137, 142, 146, 151, 156, 157, 161, 166, 171, 176, 180, 181, 186, 191, 196, 197, 202, 207, 211, 216, 217, 222, 226
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2017

Keywords

Comments

a(n) - a(n-1) is in {1,4,5} 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, 2, 1, 0, 0, 3, 2, 1, 1, 0, 3, 2, 2, 1, 0, 3, 2, 1, 0, 3, with
0 in positions given by A287578,
1 in positions given by A287579,
2 in positions given by A287580,
3 in positions given by A287577.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
    Flatten[Position[s, 0]]; (* A287577 *)
    Flatten[Position[s, 1]]; (* A287578 *)
    Flatten[Position[s, 2]]; (* A287579 *)
    Flatten[Position[s, 3]]; (* A287580 *)

A287580 Positions of 3 in A287576.

Original entry on oeis.org

2, 7, 12, 13, 17, 22, 27, 32, 36, 37, 42, 47, 51, 56, 57, 62, 67, 72, 73, 78, 82, 87, 92, 93, 97, 102, 107, 112, 116, 117, 122, 127, 132, 133, 138, 143, 147, 152, 153, 158, 162, 167, 172, 173, 177, 182, 187, 192, 193, 198, 203, 208, 212, 213, 218, 223, 227
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2017

Keywords

Comments

a(n) - a(n-1) is in {1,4,5} 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, 1, 0, 3, 3, 2, 1, 0, 0, 3, 2, 1, 1, 0, 3, 2, 1, 0, 3, 2, with
0 in positions given by A287579,
1 in positions given by A287580,
2 in positions given by A287577,
3 in positions given by A287578.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
    Flatten[Position[s, 0]]; (* A287577 *)
    Flatten[Position[s, 1]]; (* A287578 *)
    Flatten[Position[s, 2]]; (* A287579 *)
    Flatten[Position[s, 3]]; (* A287580 *)

Formula

a(n) = 4n - A287576(n) for n >= 1.

A287578 Positions of 1 in A287576.

Original entry on oeis.org

4, 5, 10, 15, 19, 24, 25, 30, 34, 39, 44, 45, 49, 54, 59, 64, 65, 70, 75, 80, 84, 85, 90, 95, 99, 104, 105, 110, 114, 119, 124, 125, 130, 135, 140, 141, 145, 150, 155, 160, 164, 165, 170, 175, 179, 184, 185, 190, 195, 200, 201, 206, 210, 215, 220, 221, 225
Offset: 1

Views

Author

Clark Kimberling, Jun 01 2017

Keywords

Comments

a(n) - a(n-1) is in {1,4,5} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 0, 3, 2, 1, 1, 0, 3, 2, 2, 1, 0, 3, 3, 2, 1, 0, 3, 2, 1, 0, with
0 in positions given by A287577,
1 in positions given by A287578,
2 in positions given by A287579,
3 in positions given by A287580.

Crossrefs

Programs

  • Mathematica
    s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9];   (* A287576 *)
    Flatten[Position[s, 0]]; (* A287577 *)
    Flatten[Position[s, 1]]; (* A287578 *)
    Flatten[Position[s, 2]]; (* A287579 *)
    Flatten[Position[s, 3]]; (* A287580 *)

Formula

a(n) = 4n - A287576(n) for n >= 1.
Showing 1-4 of 4 results.