A199841 Number of -2..2 arrays x(0..n-1) of n elements with zero sum and no element more than one greater than the previous.

1, 3, 8, 23, 66, 192, 575, 1739, 5307, 16304, 50381, 156408, 487398, 1523663, 4776107, 15006513, 47247134, 149023605, 470794024, 1489462276, 4718330397, 14964219411, 47509518289, 150982994162, 480243297965, 1528796563830, 4870415108094

Offset: 1

Author

R. H. Hardin Nov 11 2011

Keywords

• nonn

Comments

Column 2 of A199847

Examples

			Some solutions for n=6
..2...-1....2....1....2....1....1....1....1...-1....2....1....1....1....1....1
..1....0....0...-1....1....1....2....1...-1....0....2....1....1....2....0....0
.-2....1....1....0....2....0....0....0...-1....1...-2....1....1....1....0...-1
.-1....0...-2....0...-1...-1....0....1....0....1...-1....0...-1...-1....0....0
..0....1...-1....0...-2....0...-2...-2....0....1...-1...-1....0...-1....1....0
..0...-1....0....0...-2...-1...-1...-1....1...-2....0...-2...-2...-2...-2....0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200