OFFSET
1,1
COMMENTS
A word w of length n avoids abelian K-th powers circularly if every abelian K-th power in w^{K+1} has a block length of at least n. An abelian 4th power means a concatenation of four blocks that are permutations of each other, e.g., (011)(101)(110)(101) is an abelian 4th power of block length 3.
LINKS
Jarkko Peltomäki, Markus A. Whiteland, Avoiding abelian powers cyclically, arXiv:2006.06307 [cs.FL], 2020.
EXAMPLE
a(6) = 6, and the words are 000111, 001110, 011100 and their complements. The word w = 010011 does not avoid abelian 4th powers circularly because w^3 has abelian 4th power of period 2 starting at position 6.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Jarkko Peltomäki, May 13 2020
STATUS
approved