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A133235
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Numerical encoding of a series of binary words generated by a recurrence - see comments.
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2
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22, 2222, 22211222, 22211222211222, 222112222112211222211222, 2221122221122112222112222112211222211222, 222112222112211222211222211221122221122112222112222112211222211222
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OFFSET
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0,1
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COMMENTS
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The sequence of words is bb, bbbb, bbbaabbb, bbbaabbbbaabbb, bbbaabbbbaabbaabbbbaabbb, ... given by the rule that the n-th word consists of the (n-1)st word, followed by the inverse of the (n-3)rd word, followed by the (n-1)st word.
Here a (or 1) and 2 (or b) represent the respective matrices
[1 1] [2 1]
[1 0] [1 0]
arising in the study of Markov numbers (A002559) - see link.
Question: Can this substitution-deletion system be described by a simple morphism of the type shown in A008352?
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LINKS
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EXAMPLE
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a(4) = bbbaabbbbaabbaabbbbaabbb, a(2) = bbbaabbb, so a(5) = bbbaabbbbaabbaabbbbaabbb (bbbaabbb)^(-1) bbbaabbbbaabbaabbbbaabbb = bbbaabbbbaabbaabbbbaabbbbaabbaabbbbaabbb
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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