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A208943
Number of n-bead necklaces labeled with numbers -6..6 not allowing reversal, with sum zero with no three beads in a row equal.
0
1, 7, 42, 366, 3376, 33468, 344456, 3656654, 39711890, 439202182, 4929418548, 56004017042, 642825693604
OFFSET
1,2
COMMENTS
Column 6 of A208945.
EXAMPLE
Some solutions for n=5:
.-4...-4...-3...-5...-4...-2...-3...-6...-6...-6...-4...-5...-3...-4...-2...-5
..2...-3....4....6....6...-1....1....1....1...-3....4....2...-2....4...-1....5
..0....2...-2...-2....3....2....0...-2...-4....1....3...-3...-3....6...-2...-3
..1....1....1...-3...-3...-2...-3....3....4....4....0....0....2...-3...-1...-2
..1....4....0....4...-2....3....5....4....5....4...-3....6....6...-3....6....5
CROSSREFS
Sequence in context: A025593 A218124 A048862 * A209071 A174224 A278571
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 03 2012
STATUS
approved