A221427 Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without consecutive moves in the same direction

1, 217, 4390, 194879, 6688747, 250167826, 9077677881, 333226472511, 12173165267828, 445650138090486, 16298689612917528, 596369615071847374, 21816211474871696352, 798162015570301300322, 29199761336459862799952

Offset

1,2

Comments

Column 4 of A221429

Links

R. H. Hardin, Table of n, a(n) for n = 1..30

Example

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

Crossrefs

Sequence in context: A320715 A183778 A250448 * A086026 A100794 A048258

Adjacent sequences: A221424 A221425 A221426 * A221428 A221429 A221430

Keyword

nonn

Author

R. H. Hardin Jan 15 2013

Status

approved