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A209114
Number of n-bead necklaces labeled with numbers -7..7 not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.
0
1, 8, 55, 559, 5935, 67681, 802125, 9804610, 122616851, 1561658960, 20184817925, 264098109360
OFFSET
1,2
COMMENTS
Column 7 of A209115.
EXAMPLE
Some solutions for n=6:
.-6...-5...-6...-6...-7...-6...-7...-5...-4...-7...-7...-4...-7...-7...-6...-6
.-3....7...-3...-3...-3....4...-3....6....3....2...-2....1....1....5...-6....2
..2....3...-4....6....5....0....4....1....0....3....4....0....6...-5....2...-2
.-2...-4....6...-6....7...-3....4....2...-4...-2...-3....2....0...-1....3....6
..3...-4....6....6....4....1....4...-4....3....0....7....2....5....3....3...-2
..6....3....1....3...-6....4...-2....0....2....4....1...-1...-5....5....4....2
CROSSREFS
Sequence in context: A108984 A264342 A230963 * A264644 A144748 A160429
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 05 2012
STATUS
approved