A220403 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..1 nX3 array

2, 17, 122, 720, 4304, 25391, 150079, 884793, 5205467, 30603312, 179828144, 1056663902, 6208358851, 36476199327, 214305557200, 1259086948475, 7397361356851, 43460791661461, 255339657788151, 1500164308002762

Offset

1,1

Comments

Column 3 of A220406

Links

R. H. Hardin, Table of n, a(n) for n = 1..136

Example

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

Crossrefs

Sequence in context: A037754 A037642 A161128 * A097716 A073510 A291390

Adjacent sequences: A220400 A220401 A220402 * A220404 A220405 A220406

Keyword

nonn

Author

R. H. Hardin Dec 13 2012

Status

approved