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A208937
Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero with no three beads in a row equal.
0
1, 3, 12, 122, 1722, 33468, 817362, 24184890, 841286276, 33675904820, 1525641905390
OFFSET
1,2
COMMENTS
Diagonal of A208945.
EXAMPLE
Some solutions for n=5:
.-2...-4...-4...-5...-5...-5...-4...-3...-5...-1...-4...-4...-5...-4...-4...-5
.-2....0....5....0....1....0....1....4....0...-1...-4....4....3....5....0...-1
.-1...-1...-2....4....0...-2....1...-1...-3....2....1....1....0...-3....5....5
..2....4....1...-3....0....2....4...-2....5....0....2...-2....5....3...-3....4
..3....1....0....4....4....5...-2....2....3....0....5....1...-3...-1....2...-3
CROSSREFS
Sequence in context: A010571 A280248 A067124 * A209065 A124153 A162127
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 03 2012
STATUS
approved