A220239 Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and vertical neighbors in a random 0..1 nX3 array

2, 23, 148, 1131, 8127, 58091, 419164, 3016838, 21697096, 156223103, 1124229264, 8090787596, 58233550828, 419095508303, 3016219087452, 21707952324961, 156230959713801, 1124391382315226, 8092241949528463, 58239664959701115

Offset

1,1

Comments

Column 3 of A220242

Links

R. H. Hardin, Table of n, a(n) for n = 1..23

Example

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

Crossrefs

Sequence in context: A235594 A053299 A356828 * A189977 A130547 A352355

Adjacent sequences: A220236 A220237 A220238 * A220240 A220241 A220242

Keyword

nonn

Author

R. H. Hardin Dec 08 2012

Status

approved