A202506 Number of zero-sum -3..3 arrays of n elements with first through third differences also in -3..3

1, 3, 15, 29, 95, 255, 747, 2215, 6649, 19967, 60145, 182003, 554625, 1691547, 5175093, 15875649, 48789933, 150258301, 463501341, 1431832723, 4429155217, 13716674493, 42524970155, 131966196475, 409893633219, 1274208141011

Offset

1,2

Comments

Column 3 of A202511

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A147344 A201434 A308385 * A053519 A039666 A020493

Adjacent sequences: A202503 A202504 A202505 * A202507 A202508 A202509

Keyword

nonn

Author

R. H. Hardin Dec 20 2011

Status

approved