A204294 Number of n X n 0..3 arrays with every element neighboring horizontally or vertically both a 0 and a 1, and 2 introduced before 3 in row major order

0, 4, 80, 5956, 6709692, 47309058644, 2168622256129656, 736756458623041306372

Offset

1,2

Comments

Diagonal of A204301

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=4
..0..1..0..1....1..0..0..0....0..0..1..1....0..0..1..2....0..0..1..1
..0..1..0..1....1..2..1..1....1..1..2..0....1..2..1..0....1..1..0..0
..0..1..0..0....0..0..0..0....0..0..0..0....1..3..1..0....1..0..2..0
..0..1..1..0....0..1..1..1....0..1..1..1....0..0..1..1....3..0..1..1

Crossrefs

Sequence in context: A000316 A012106 A156103 * A203480 A339854 A116189

Adjacent sequences: A204291 A204292 A204293 * A204295 A204296 A204297

Keyword

nonn

Author

R. H. Hardin Jan 14 2012

Status

approved