A301837 Number of nX4 0..1 arrays with every element equal to 0, 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 81, 678, 5748, 48802, 414385, 3518619, 29877293, 253694309, 2154171994, 18291531681, 155317282580, 1318832060857, 11198483378779, 95088702916552, 807418390272882, 6855961191710593, 58215423910060190, 494319539779559696

Offset: 1

Author

R. H. Hardin, Mar 27 2018

Keywords

• nonn

Comments

Column 4 of A301841.

Examples

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

Links

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

Crossrefs

Cf. A301841.

Formula

Empirical: a(n) = 13*a(n-1) -46*a(n-2) +72*a(n-3) -57*a(n-4) +16*a(n-5) for n>6