A221831 Number of 4Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns.

0, 64, 2930, 115417, 4715043, 192788993, 7888216533, 322723834959, 13203608881221, 540203150208573, 22101534579211095, 904249026745794715, 36995912673327194833, 1513629078095632460534, 61927733346071816062294

Offset: 1

Author

R. H. Hardin Jan 26 2013

Keywords

• nonn

Comments

Row 4 of A221828

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..25