A221395 Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two

4, 54, 631, 7678, 93398, 1137850, 13857444, 168717375, 2053766992, 24997337148, 304235229651, 3702632940296, 45061321786573, 548394286665966, 6673898631211550, 81220384265578677, 988438827804013263

Offset

1,1

Comments

Column 4 of A221396

Links

R. H. Hardin, Table of n, a(n) for n = 1..51

Example

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

Crossrefs

Sequence in context: A073863 A269480 A199022 * A357558 A241126 A089205

Adjacent sequences: A221392 A221393 A221394 * A221396 A221397 A221398

Keyword

nonn

Author

R. H. Hardin Jan 14 2013

Status

approved