A202130 Number of zero-sum nX1 -3..3 arrays with every element equal to at least one horizontal or vertical neighbor

0, 1, 1, 7, 5, 43, 43, 275, 371, 1913, 3017, 14305, 25039, 109803, 212645, 866361, 1818147, 6992905, 15653093, 57383555, 135498383, 477220531, 1177254905, 4012238901, 10256656225, 34031432595, 89553075529, 290731277941

Offset

1,4

Comments

Column 1 of A202134

Links

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

Example

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

Crossrefs

Sequence in context: A142883 A146382 A163742 * A089244 A063003 A038271

Adjacent sequences: A202127 A202128 A202129 * A202131 A202132 A202133

Keyword

nonn

Author

R. H. Hardin Dec 11 2011

Status

approved