A288713 Positions of 1 in A288711; complement of A288712.

1, 7, 13, 17, 23, 29, 33, 39, 43, 49, 55, 59, 65, 71, 75, 81, 85, 91, 97, 101, 107, 111, 117, 123, 127, 133, 139, 143, 149, 153, 159, 165, 169, 175, 181, 185, 191, 195, 201, 207, 211, 217, 221, 227, 233, 237, 243, 249, 253, 259, 263, 269, 275, 279, 285, 289

Offset

1,2

Comments

Conjecture: a(n)/n-> 3 + sqrt(5), and if m denotes this number, then -1 < m - a(n)/n) < 5 for n >= 1.

The truth of this conjecture follows directly from the same statement for A288709, in combination with Mathar's Jun 19 2017 conjecture. - Michel Dekking, Oct 20 2018

Appears to differ from A288709 only at a(1). - R. J. Mathar, Jun 19 2017

From Michel Dekking, Oct 20 2018: (Start)

Here is a proof of this conjecture.

The sequence (a(n)) consists of the positions of 1 in A288711, which can be obtained from A289034 by a [0->00, 1->10]-transform (see Kimberling's observation in the Comments of A288707). Similarly, the sequence A288709 consists of the positions of 1 in A288707, which can be obtained from A189661 by the same [0->00, 1->10]-transform. It is shown in the Comments of A189661 that A189661 = A289034, except for the first two terms. In A189661 these two terms are 0,1, which is transformed to 0,0,1,0. In A289034 these two terms are 1,0, which is transformed to 1,0,0,0. We see that the first 1 in A288711 occurs at position 1, but the first 1 in A288707 appears at position 3. The next 1's will occur at the same position in the two sequences.

Conclusion: the sequence (a(n)) only differs from A288709 at a(1). (End)

Links

Clark Kimberling, Table of n, a(n) for n = 1..10000

Formula

a(n+1) = 2*floor(n*phi) +2*n + 3, where phi = (1+sqrt(5))/2. - Michel Dekking, Oct 20 2018

Mathematica

s = {0, 0}; w[0] = StringJoin[Map[ToString, s]];
w[n_] := StringReplace[w[n - 1], {"00" -> "1000", "10" -> "00"}]
Table[w[n], {n, 0, 8}]
st = ToCharacterCode[w[9]] - 48   (* A288711 *)
Flatten[Position[st, 0]]  (* A288712 *)
Flatten[Position[st, 1]]  (* A288713 *)

Prog

(Magma) [1] cat [2*Floor(n*(1 + Sqrt(5)) / 2) + 2*n + 3: n in [1..60]]; // Vincenzo Librandi, Oct 20 2018

Crossrefs

Cf. A288711, A288712.

Sequence in context: A180263 A002733 A108334 * A136083 A167276 A181570

Adjacent sequences: A288710 A288711 A288712 * A288714 A288715 A288716

Keyword

nonn,easy

Author

Clark Kimberling, Jun 16 2017

Status

approved