A221901 Number of 4 X n arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns.

13, 2305, 235332, 25821731, 2815434576, 307126807101, 33499434763000, 3654072363322660, 398576690257243663, 43475776796985596792, 4742231413650315959473

Offset: 1

Author

R. H. Hardin Jan 30 2013

Keywords

• nonn

Comments

Row 4 of A221898.

Examples

			Some solutions for n=3
..1..0..1....0..2..0....0..1..2....0..2..1....0..0..2....0..0..0....0..2..1
..0..3..2....1..1..2....2..0..1....2..0..1....4..0..0....2..2..2....1..1..0
..1..0..1....0..0..3....1..0..2....0..2..4....1..0..0....1..0..0....2..2..2
..2..0..1....2..1..0....0..3..0....0..0..0....0..5..0....2..1..2....0..0..1
		

Crossrefs

Cf. A221898.