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A324149
Least integer x such that every set of the length-n subwords of some binary word y is achievable by taking the subwords of some word of length <= x.
4
2, 5, 10, 24, 77
OFFSET
1,1
COMMENTS
Another way to say this is that a(n) is the least integer x such that every subset of vertices encountered by some walk on the de Bruijn graph of order n is achievable by a walk of length <= x-n (length = number of edges).
The original definition was: "Maximal length of the shortest non-circular witness over all representable sets of binary vectors of length n.".
LINKS
Shuo Tan and Jeffrey Shallit, Sets represented as the length-n factors of a word, preprint, arXiv:1304.3666 [cs.FL], 2013.
EXAMPLE
For n = 1,2,3,4 examples of a longest word (whose set of length-n subwords did not appear as the subwords of any shorter word) are 01, 00110, 0001011100, 000010010101100101101111.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Feb 26 2019
EXTENSIONS
Updated by Jeffrey Shallit, Sep 05 2024; edited by N. J. A. Sloane, Nov 03 2024
STATUS
approved