A208989 Number of n-bead necklaces labeled with numbers -4..4 not allowing reversal, with sum zero and first differences in -4..4.

1, 3, 7, 33, 159, 874, 4935, 28816, 171413, 1036611, 6350875, 39346156, 246076193, 1551630136, 9853551873, 62966367376, 404595868611

Offset

1,2

Comments

Column 4 of A208993.

Links

Table of n, a(n) for n=1..17.

Example

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

Crossrefs

Sequence in context: A051256 A057795 A054935 * A358961 A024496 A081890

Adjacent sequences: A208986 A208987 A208988 * A208990 A208991 A208992

Keyword

nonn

Author

R. H. Hardin, Mar 04 2012

Status

approved