A202247 Number of zero-sum -3..3 arrays of n elements with adjacent element differences also in -3..3

1, 3, 17, 81, 397, 2003, 10239, 52697, 273021, 1422337, 7442827, 39091861, 205972443, 1088212379, 5762943375, 30582601227, 162591973175, 865826349887, 4617379607829, 24656446918287, 131820057982369, 705507882790695

Offset

1,2

Comments

Column 3 of A202252

Links

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

Example

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

Crossrefs

Sequence in context: A217958 A093568 A164305 * A225342 A362390 A194596

Adjacent sequences: A202244 A202245 A202246 * A202248 A202249 A202250

Keyword

nonn

Author

R. H. Hardin Dec 14 2011

Status

approved