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A208715
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Number of n-bead necklaces labeled with numbers 1..n allowing reversal, with no adjacent beads differing by more than 1.
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1
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1, 3, 7, 18, 38, 100, 224, 600, 1498, 4124, 11054, 31347, 87887, 253251, 727867, 2117551, 6159994, 18022052, 52757222, 154874172, 454989753, 1338737083, 3941860229, 11618101775, 34264747423, 101127761931, 298632667837, 882370316215, 2608423280534, 7714578529582
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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EXAMPLE
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All solutions for n=3:
..2....2....1....3....2....1....1
..2....2....1....3....3....2....1
..2....3....2....3....3....2....1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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