A184059 Number of strings of n+2 numbers x(i) in -7..7 with the sum of x(i) equal to zero and the sums of x(i)*x(i+1) and x(i)*x(i+2) equal to each other

1, 33, 245, 2145, 35451, 496519

Offset

1,2

Comments

Column 7 of A184061

Links

Table of n, a(n) for n=1..6.

Example

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

Crossrefs

Sequence in context: A271208 A343499 A318744 * A197347 A344524 A197398

Adjacent sequences: A184056 A184057 A184058 * A184060 A184061 A184062

Keyword

nonn

Author

R. H. Hardin Jan 09 2011

Status

approved