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 1-2 of 2 results.

A284395 Positions of 1 in A284394.

Original entry on oeis.org

2, 8, 17, 23, 32, 41, 47, 56, 62, 71, 80, 86, 95, 104, 110, 119, 125, 134, 143, 149, 158, 164, 173, 182, 188, 197, 206, 212, 221, 227, 236, 245, 251, 260, 269, 275, 284, 290, 299, 308, 314, 323, 329, 338, 347, 353, 362, 371, 377, 386, 392, 401, 410, 416, 425
Offset: 1

Views

Author

Clark Kimberling, May 02 2017

Keywords

Comments

The sequences p = A032766, q = A285395, 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, A284394 = 01002001002002001..., in which the positions of 1 are 2,8,17,...
		

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 *)

A284396 Positions of 2 in A284394.

Original entry on oeis.org

5, 11, 14, 20, 26, 29, 35, 38, 44, 50, 53, 59, 65, 68, 74, 77, 83, 89, 92, 98, 101, 107, 113, 116, 122, 128, 131, 137, 140, 146, 152, 155, 161, 167, 170, 176, 179, 185, 191, 194, 200, 203, 209, 215, 218, 224, 230, 233, 239, 242, 248, 254, 257, 263, 266, 272
Offset: 1

Views

Author

Clark Kimberling, May 02 2017

Keywords

Comments

The sequences p = A032766, q = A285395, 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, A284394 = 01002001002002001..., in which the positions of 2 are 5,11,14,...
		

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, conjectured *)
    Flatten[Position[st, 1]]  (* A284395 *)
    Flatten[Position[st, 2]]  (* A284396 *)

Formula

a(n) = 3*floor(n*phi) + 2. This follows from Theorem 29 in Allouche and Dekking, since the overlap word 10101 that contains 101 does not occur in the Fibonacci word. Note that v = 3*phi. - Michel Dekking, Oct 17 2018
Showing 1-2 of 2 results.