A183943 Number of strings of n numbers x(i) in -8..8 with sums of x(i) and of x(i)*x(i+1) both zero

1, 1, 17, 69, 1417, 9335, 135793, 1639099, 23586625, 323498939, 4919390397, 73971159473, 1157160667507

Offset

1,3

Comments

Column 8 of A183944

Links

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

Example

Some solutions for n=4
..3....6....3...-4....7...-2...-3...-8....0...-4....8....2....5...-2....0....0
..0....0....6....0....0....0....0....2....7....1....0....0....0...-4....8...-3
..0...-6...-6....0...-7....2....3....4....0....2...-8....0...-5...-2....0....0
.-3....0...-3....4....0....0....0....2...-7....1....0...-2....0....8...-8....3

Crossrefs

Sequence in context: A041556 A041558 A327495 * A180532 A179038 A179039

Adjacent sequences: A183940 A183941 A183942 * A183944 A183945 A183946

Keyword

nonn

Author

R. H. Hardin Jan 08 2011

Status

approved