A217223 Number of nX3 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no 2-loops and with no occupancy greater than 2

0, 7, 112, 1648, 22914, 311988, 4202440, 56306491, 752377824, 10039480767, 133868165460, 1784368349249, 23779898954002, 316879002290160, 4222360270783970, 56260809604666184, 749636868848349394

Offset

1,2

Comments

Column 3 of A217227

Links

R. H. Hardin, Table of n, a(n) for n = 1..18

Example

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

Crossrefs

Sequence in context: A163700 A094219 A212702 * A067404 A129030 A128576

Adjacent sequences: A217220 A217221 A217222 * A217224 A217225 A217226

Keyword

nonn

Author

R. H. Hardin Jan 07 2013

Status

approved