A220957 Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..3 nX3 array

2, 19, 142, 1224, 9500, 74689, 569829, 4381255, 33461868, 256031511, 1955686977, 14946638627, 114189416236, 872513727055, 6666226304246, 50933590756690, 389152279872760, 2973302144607117, 22717282312449506, 173570028191252613

Offset

1,1

Comments

Column 3 of A220959

Links

R. H. Hardin, Table of n, a(n) for n = 1..109

Example

Some solutions for n=3
..0..1..0....0..1..0....0..1..0....0..1..0....1..0..0....1..0..1....0..1..0
..0..1..0....0..1..0....1..0..1....1..0..0....0..0..0....0..0..0....1..1..0
..1..1..1....0..0..0....1..0..0....1..0..1....0..0..0....1..0..0....0..1..0

Crossrefs

Sequence in context: A178829 A166298 A220792 * A280546 A323141 A319962

Adjacent sequences: A220954 A220955 A220956 * A220958 A220959 A220960

Keyword

nonn

Author

R. H. Hardin Dec 26 2012

Status

approved