A302006 Number of nX4 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 128, 1808, 25808, 368144, 5251712, 74917424, 1068722240, 15245681888, 217484775440, 3102493407248, 44258111045072, 631356826964288, 9006517303652528, 128480995970256128, 1832824583461859168

Offset: 1

Author

R. H. Hardin, Mar 30 2018

Keywords

• nonn

Comments

Column 4 of A302010.

Examples

			Some solutions for n=5
..0..0..0..1. .0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..0..0
..1..0..1..0. .0..1..1..0. .1..1..0..0. .1..1..0..0. .1..1..1..1
..0..0..1..0. .0..1..1..0. .1..1..0..0. .1..0..1..1. .1..0..1..1
..0..0..1..0. .0..1..0..0. .1..0..1..1. .0..0..1..1. .0..0..0..1
..0..1..0..0. .1..1..0..0. .1..1..1..1. .0..1..0..0. .1..1..1..0
		

Links

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

Crossrefs

Cf. A302010.

Formula

Empirical: a(n) = 13*a(n-1) +18*a(n-2) +a(n-3) -4*a(n-4)