A221509 Number of 3Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.

0, 64, 664, 31663, 730874, 22664752, 617892584, 17782943460, 499912745268, 14194927933912, 401323009766448, 11367289765226164, 321716709992052606, 9108319376609834007, 257833317722010551358, 7299063007433073641077

Offset: 1

Author

R. H. Hardin Jan 18 2013

Keywords

• nonn

Comments

Row 3 of A221507

Examples

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