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A209072
Number of n-bead necklaces labeled with numbers -7..7 not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.
0
1, 8, 56, 563, 6006, 68723, 817594, 10030238, 125899533, 1609360719, 20877938573, 274173012896
OFFSET
1,2
COMMENTS
Column 7 of A209073.
EXAMPLE
Some solutions for n=6:
.-7...-5...-7...-7...-7...-6...-7...-6...-5...-7...-5...-7...-6...-6...-6...-5
.-6....0....4....4...-6....3...-2....5....0....3...-3...-4....7...-2....5....5
..1...-4....6....2....4....6....3....5....4....2....6....2...-5....1...-4...-3
..1....3...-4....0....7....2....4....0....2....0....2....6....2....4....1....5
..4...-1...-2...-3....4...-4....0...-1...-3....1....1....5....4....5....3....0
..7....7....3....4...-2...-1....2...-3....2....1...-1...-2...-2...-2....1...-2
CROSSREFS
Sequence in context: A009107 A209665 A208944 * A133671 A326239 A154411
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2012
STATUS
approved