A209111 Number of n-bead necklaces labeled with numbers -4..4 not allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.

1, 5, 19, 120, 741, 5032, 35253, 255821, 1898309, 14350653, 110094949, 855048115, 6709326541, 53110380781

Offset

1,2

Comments

Column 4 of A209115.

Links

Table of n, a(n) for n=1..14.

Example

Some solutions for n=6:
.-4...-3...-4...-4...-4...-4...-3...-3...-4...-3...-3...-4...-3...-4...-4...-4
.-1....0...-3....2....3....0....3...-3....0...-1...-1....3....3...-4....0....1
..2....1...-3...-3....2....4...-2....3....3...-3....0....4...-3....3....4....2
..3....0....4....4...-3...-1....2....2....3....4...-2...-3....4....4...-2....0
..3....2....2....4....2...-2....1...-1....1....1....3....1....1....0...-2....4
.-3....0....4...-3....0....3...-1....2...-3....2....3...-1...-2....1....4...-3

Crossrefs

Sequence in context: A199480 A339079 A357361 * A354863 A328060 A366340

Adjacent sequences: A209108 A209109 A209110 * A209112 A209113 A209114

Keyword

nonn

Author

R. H. Hardin, Mar 05 2012

Status

approved