A219749 In the string b12b2b12 replace b with n 1's.

11212112, 11121121112, 11112111211112, 11111211112111112, 11111121111121111112, 11111112111111211111112, 11111111211111112111111112, 11111111121111111121111111112, 11111111112111111111211111111112, 11111111111211111111112111111111112

Offset

1,1

Links

Table of n, a(n) for n=1..10.

J. Berstel, A. Lauve, C. Reutenauer & F. Saliola, Combinatorics on Words: Christoffel Words and Repetitions in Words, 2008, see p. 110.

Aviezri S. Fraenkel and Jamie Simpson, How Many Squares Can a String Contain?, Journal of Combinatorial Theory, Series A 82, 112-120 (1998).

Mathematica

rb1[n_]:=Module[{c=PadRight[{}, n, 1]}, FromDigits[Join[c, {1, 2}, c, {2}, c, {1, 2}]]]; Array[rb1, 10] (* Harvey P. Dale, Sep 24 2017 *)

Crossrefs

Cf. A219750.

Sequence in context: A331360 A232445 A187375 * A219750 A201253 A273879

Adjacent sequences: A219746 A219747 A219748 * A219750 A219751 A219752

Keyword

nonn

Author

N. J. A. Sloane, Nov 28 2012

Status

approved