A267725 Number of 2Xn arrays containing n copies of 0..2-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0.

0, 1, 1, 3, 5, 12, 26, 60, 143, 353, 879, 2200, 5528, 13963, 35421, 90122, 229729, 586438, 1498966, 3836099, 9827905, 25202549, 64683193, 166137751, 427022480, 1098291533, 2826500851, 7278246356, 18751418071, 48334451894, 124647030884

Offset: 1

Author

R. H. Hardin, Jan 20 2016

Keywords

• nonn

Comments

Row 2 of A267724.

Examples

			Some solutions for n=6
..0..0..1..1..0..0....0..0..1..1..1..1....0..0..1..1..0..0....0..0..0..0..0..0
..0..0..1..1..1..1....0..0..0..0..1..1....1..1..1..1..0..0....1..1..1..1..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A267724.