A268160 Number of 3Xn arrays containing n copies of 0..3-1 with every element equal to at least one vertical or antidiagonal neighbor and the top left element equal to 0.

0, 0, 8, 14, 52, 1516, 7582, 46338, 501270, 3535396, 25480614, 220369120, 1716544860, 13279246254, 108919001860, 873463942418, 6971258302462, 56716000746978, 460015101808320, 3726764125840338, 30399952923410062

Offset: 1

Author

R. H. Hardin, Jan 27 2016

Keywords

• nonn

Comments

Row 3 of A268159.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..68

Crossrefs

Cf. A268159.