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A208808
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Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and three times sum of squares <= n*(2)*(2+1).
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0
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1, 2, 5, 15, 59, 187, 753, 3125, 12503, 54977, 229533, 1010861, 4476937, 19717931, 89279611, 400928643, 1825710727, 8356818535, 38284519557, 177041554325
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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=6:
.-1...-2...-2...-2...-2...-2...-1...-2...-2...-2...-2...-2...-2...-1...-1...-2
.-1...-1...-1....1....1....2...-1....1....0...-1....0...-1....1...-1...-1...-1
..0....2....1....0....2...-1....2....1....1....1...-1....1....0....1....0....1
..0....1....2....1...-1....0....0....1....0....2....2....1...-1....1....2....0
..1...-1....1...-1....1....1...-1...-1....0...-1....1....2....2...-1...-1....0
..1....1...-1....1...-1....0....1....0....1....1....0...-1....0....1....1....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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