A221187 Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nX4 array

4, 107, 2648, 51924, 928133, 15638551, 256020803

Offset

1,1

Comments

Column 4 of A221188

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A104595 A356201 A222930 * A220531 A322085 A128865

Adjacent sequences: A221184 A221185 A221186 * A221188 A221189 A221190

Keyword

nonn

Author

R. H. Hardin Jan 04 2013

Status

approved