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A093382
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a(n) = length k of longest binary sequence x(1) ... x(k) such that for no n <= i < j <= k/2 is x(i) ... x(2i) a subsequence of x(j) ... x(2j).
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6
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OFFSET
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1,1
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COMMENTS
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Doesn't the binary sequence 000010011001110011101010101010101010101100110 demonstrate that a(2)>=45 ? - R. J. Mathar, Jul 29 2007 Answer: No - see the following comment.
The sequence of length 45 above does not satisfy the requirements of the definition: Subsequences are not required to be consecutive. Therefore it cannot show a(2)>=45. In the sequence we find for i=2, j=3: x(i..2i) is 000; x(j..2j) is 001001; and 000 is a subsequence of 001001. - Don Reble, May 13 2008
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REFERENCES
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a(1) - a(3) computed by R. Dougherty, who finds that a(4) >= 187205.
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LINKS
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EXAMPLE
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a(1) = 11 from 01110000000.
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CROSSREFS
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KEYWORD
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nonn,bref,nice,more
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AUTHOR
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STATUS
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approved
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