A082380 Number of 7/3+-power-free words over the alphabet {0,1}.

1, 2, 4, 6, 10, 14, 20, 30, 38, 50, 64, 86, 108, 136, 178, 222, 276, 330, 408, 500, 618, 774, 962, 1178, 1432, 1754, 2160, 2660, 3292

Offset

0,2

Links

Table of n, a(n) for n=0..28.

J. Karhumäki and J. Shallit, Polynomial vs Exponential Growth in Repetition-Free Binary Words

A. M. Shur, Growth properties of power-free languages, Computer Science Review, Vol. 6 (2012), 187-208.

A. M. Shur, Numerical values of the growth rates of power-free languages, arXiv:1009.4415 [cs.FL], 2010.

Formula

Let L = lim a(n)^(1/n); then L exists since a(n) is submultiplicative. 1.2206318 < L < 1.22064482 (Shur 2012); the gap between the bounds can be made less than any given constant. Empirically, the upper bound is precise: L=1.2206448... . - Arseny Shur, Apr 26 2015

Crossrefs

Cf. A038952, A028445, A007777, A082379.

Sequence in context: A103257 A103259 A280131 * A238871 A323595 A136460

Adjacent sequences: A082377 A082378 A082379 * A082381 A082382 A082383

Keyword

nonn

Author

Ralf Stephan, Apr 10 2003

Extensions

Changed name by Jeffrey Shallit, Sep 26 2014

Status

approved