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A209107 Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2. 0
1, 3, 11, 120, 1683, 32802, 802125, 23766209, 827695021, 33165786247 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A209115.

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for n=6:

.-5...-4...-6...-4...-6...-6...-5...-6...-6...-4...-6...-6...-4...-4...-4...-5

..0...-4...-1...-2...-4....0...-1....4....6....5....5....6....0....1...-2...-1

.-1....6....6....5....6...-5....6....0...-5...-3....4....2....0....2....3...-2

..5...-1...-6....4....6....6...-2....1...-1....5....1...-2....2....1....1...-4

.-3...-1....4....0....2....2....4...-4....5...-3...-5...-2...-1....2....0....6

..4....4....3...-3...-4....3...-2....5....1....0....1....2....3...-2....2....6

CROSSREFS

Sequence in context: A036930 A198085 A319749 * A015047 A339326 A102847

Adjacent sequences:  A209104 A209105 A209106 * A209108 A209109 A209110

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 05 2012

STATUS

approved

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Last modified October 19 09:36 EDT 2021. Contains 348074 sequences. (Running on oeis4.)