

A028445


Number of cubefree words of length n on two letters.


9



2, 4, 6, 10, 16, 24, 36, 56, 80, 118, 174, 254, 378, 554, 802, 1168, 1716, 2502, 3650, 5324, 7754, 11320, 16502, 24054, 35058, 51144, 74540, 108664, 158372, 230800, 336480, 490458, 714856, 1041910, 1518840, 2213868
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Table of n, a(n) for n=1..36.
A. E. Edlin, Cubefree words
Mari Huova, Combinatorics on Words. New Aspects on Avoidability, Defect Effect, Equations and Palindromes, Turku Centre for Computer Science, TUCS Dissertations No 172, April 2014.
K. Jarhumaki and J. Shallit, Polynomial vs Exponential Growth in RepetitionFree Binary Words, arXiv:math/0304095 [math.CO], 2003.
Eric Weisstein's World of Mathematics, Cubefree Word.


CROSSREFS

Cf. A007777, A082379, A082380.
Sequence in context: A098151 A132002 A211971 * A006305 A067247 A017985
Adjacent sequences: A028442 A028443 A028444 * A028446 A028447 A028448


KEYWORD

nonn


AUTHOR

Anne Edlin (anne(AT)euclid.math.temple.edu)


EXTENSIONS

a(29)a(36) from Lars Blomberg, Aug 22 2013


STATUS

approved



