A220404 Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..1 nX4 array

4, 40, 908, 10989, 139233, 1782679, 22578152, 286030234, 3627899762

Offset

1,1

Comments

Column 4 of A220406

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A013053 A055128 A117251 * A211040 A012957 A012977

Adjacent sequences: A220401 A220402 A220403 * A220405 A220406 A220407

Keyword

nonn

Author

R. H. Hardin Dec 13 2012

Status

approved