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A209068
Number of n-bead necklaces labeled with numbers -3..3 not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2.
0
1, 4, 12, 57, 276, 1465, 8008, 45408, 263168, 1554582, 9318412, 56549840, 346717662, 2144555617, 13365472929, 83848948043, 529091046781, 3355802952070
OFFSET
1,2
COMMENTS
Column 3 of A209073.
EXAMPLE
Some solutions for n=6:
.-2...-2...-2...-3...-2...-2...-3...-3...-2...-2...-3...-2...-2...-3...-3...-3
..0...-1....1....2....2....2....3...-1...-2....2....1....3...-1...-3....1....3
..1....3....2....1...-1....0....1....0....3....0....3....1....1....3....1....2
.-1....0...-1...-2....3....1....3....3...-1...-2...-1...-1....2....2....0....0
..3...-1....0....3...-1....0...-2...-1....0....3....1....0....1....3...-1...-1
.-1....1....0...-1...-1...-1...-2....2....2...-1...-1...-1...-1...-2....2...-1
CROSSREFS
Cf. A209073.
Sequence in context: A197924 A065125 A208940 * A177265 A243923 A192331
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2012
STATUS
approved