A209341 Number of n-bead necklaces labeled with numbers -5..5 allowing reversal, with sum zero with no three beads in a row equal.

1, 6, 17, 128, 883, 7358, 62853, 563109, 5153746, 48127107, 456011561, 4374662802, 42398844001

Offset

1,2

Comments

Column 5 of A209344.

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=7:
.-4...-5...-5...-5...-3...-3...-5...-4...-3...-5...-3...-4...-4...-5...-4...-3
.-3....1...-4....2...-2....0....0...-1....1....3...-1...-1...-2...-2...-2...-2
..1....3....0....2....0....3...-3....2....2....0....5....5....1....1....5....0
..4....1....5...-3....2...-1....5....0...-2...-2...-2...-3....2....0...-4....5
.-3...-2....4...-2....0...-1....4....2...-2...-2....1...-3....0....5....0...-3
..4...-1...-1....2....0...-2...-5...-1....0....2...-2....1...-1...-3....1....3
..1....3....1....4....3....4....4....2....4....4....2....5....4....4....4....0

Crossrefs

Sequence in context: A024080 A099436 A209482 * A355787 A077022 A074923

Adjacent sequences: A209338 A209339 A209340 * A209342 A209343 A209344

Keyword

nonn

Author

R. H. Hardin, Mar 06 2012

Status

approved