A221896 Number of nX4 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, 2241, 236532, 25821731, 2814706089, 307131177266, 33498766685333, 3653989849310339, 398568427571535443, 43474867097541833158, 4742132126980966864298, 517260183698295861792396

Offset: 1

Author

R. H. Hardin Jan 30 2013

Keywords

• nonn

Comments

Column 4 of A221898

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..58