A184056 Number of strings of n+2 numbers x(i) in -4..4 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, 19, 109, 541, 4769, 40483, 327223, 2590527, 20896283, 167580009, 1349709835, 11155226611, 93502733191, 786281486125

Offset

1,2

Comments

Column 4 of A184061

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Sequence in context: A142322 A306855 A243761 * A280628 A191566 A118607

Adjacent sequences: A184053 A184054 A184055 * A184057 A184058 A184059

Keyword

nonn

Author

R. H. Hardin Jan 09 2011

Status

approved