A209029 Number of n-bead necklaces labeled with numbers -5..5 allowing reversal, with sum zero and first differences in -5..5.

1, 3, 7, 38, 187, 1237, 8235, 58524, 422504, 3117158, 23290361, 176103500, 1344136056, 10344670554, 80181862705, 625395356182, 4904914026691, 38658468142298, 306034794302017, 2432316965565820, 19401236375176220, 155259190622702818

Offset: 1

Author

R. H. Hardin, Mar 04 2012

Keywords

• nonn

Examples

			Some solutions for n=6:
.-4...-3...-2...-3...-3...-3...-3...-3...-3...-3...-3...-3...-2...-2...-2...-3
.-1....0...-1....0...-2....1....0...-2....1...-2...-2...-3....0....1....0...-2
..0....1....0....0....1....2....3....2...-3....2....2...-2....1...-1....1....1
..0....0....3....0....4...-2....0...-1....1....2....1....1....2....1....1....1
..4....2...-1....1...-1....0...-2....2....2....3....0....5...-2....0...-2....3
..1....0....1....2....1....2....2....2....2...-2....2....2....1....1....2....0
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..50

Crossrefs

Column 5 of A209032.

Extensions

a(15)-a(22) from Andrew Howroyd, Mar 12 2017