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A208823
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Number of n-bead necklaces labeled with numbers -6..6 allowing reversal, with sum zero.
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0
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1, 7, 25, 210, 1755, 17339, 177097, 1888153, 20587627, 228891069, 2582512649, 29499246456
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for n=3:
.-4...-5...-4...-6...-5...-2...-1...-3...-6...-1...-3...-6...-4...-2...-6...-4
.-2....1....0....3...-1...-1....0...-1....1...-1....1....0...-1...-2....2....2
..6....4....4....3....6....3....1....4....5....2....2....6....5....4....4....2
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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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