A201869 Number of zero-sum -4..4 arrays of n elements with first and second differences also in -4..4

1, 5, 21, 95, 443, 2191, 11107, 57203, 296293, 1541117, 8043485, 42109417, 221085605, 1163918489, 6142786425, 32491880113, 172201763497, 914222792849, 4861068133699, 25882407886253, 137978446814067, 736378930368467

Offset

1,2

Comments

Column 4 of A201873

Links

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

Example

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

Crossrefs

Sequence in context: A361775 A343349 A159289 * A017968 A017969 A050897

Adjacent sequences: A201866 A201867 A201868 * A201870 A201871 A201872

Keyword

nonn

Author

R. H. Hardin Dec 06 2011

Status

approved