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A338761
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Subword complexity of a certain infinite word.
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1
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1, 2, 4, 8, 13, 22, 37, 57, 85, 120, 165, 219, 285, 362, 453, 557, 677, 812, 965, 1135, 1325, 1534, 1765, 2017, 2293, 2592, 2917, 3267, 3645, 4050, 4485, 4949, 5445, 5972, 6533, 7127, 7757, 8422, 9125, 9865, 10645, 11464, 12325, 13227, 14173, 15162, 16197
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OFFSET
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0,2
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COMMENTS
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The infinite word is (ab)(abb.aab)(abbb.aabb.aaab)(abbbb.aabbb.aaabb.aaaab)... . Subword complexity is the number of distinct length-n blocks appearing in the sequence.
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LINKS
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FORMULA
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Equal to 2^n for n <= 3, and n^3/6-2n/3+(19+(-1)^n)/4 for n >= 4.
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EXAMPLE
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For n=4 the only subwords omitted are {abaa, baba, bbab}.
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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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