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A208986
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Number of n-bead necklaces labeled with numbers -1..1 not allowing reversal, with sum zero and first differences in -1..1.
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1
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1, 1, 1, 2, 3, 5, 9, 18, 35, 73, 151, 324, 691, 1503, 3277, 7212, 15927, 35407, 78967, 176942, 397717, 897079, 2029071, 4602438, 10464647, 23849545, 54468627, 124646180, 285762575, 656268311, 1509570433, 3477615648, 8022765075
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,4
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COMMENTS
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LINKS
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EXAMPLE
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All solutions for n=7:
..0...-1...-1...-1...-1...-1...-1...-1...-1
..0...-1...-1...-1....0....0....0....0....0
..0....0....0....0....0....0....0....1...-1
..0....1....1....0....0....0....1....0....0
..0....1....0....1....1....0....0....0....1
..0....0....1....1....0....1....0....0....1
..0....0....0....0....0....0....0....0....0
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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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