A221675 Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without move-in move-out left turns

4, 139, 5741, 229150, 9062913, 357398390, 14082457465, 554737340774, 21850499916432, 860643590653662, 33898578158279334, 1335175267629518426, 52588965509249101477, 2071337262002534945067, 81584368108175368557177

Offset

1,1

Comments

Column 4 of A221676

Links

R. H. Hardin, Table of n, a(n) for n = 1..27

Example

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

Crossrefs

Sequence in context: A089666 A363114 A029850 * A340838 A291450 A093981

Adjacent sequences: A221672 A221673 A221674 * A221676 A221677 A221678

Keyword

nonn

Author

R. H. Hardin Jan 21 2013

Status

approved