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A028445 Number of cube-free 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

REFERENCES

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; http://www.doria.fi/bitstream/handle/10024/95677/TUCSDissertation172.pdf?sequence=4

LINKS

Table of n, a(n) for n=1..36.

A. E. Edlin, Cube-free words

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

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

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Last modified July 26 13:15 EDT 2014. Contains 244946 sequences.