A302064 Number of n X 3 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

4, 25, 148, 884, 5296, 31760, 190528, 1143104, 6858496, 41150720, 246903808, 1481421824, 8888528896, 53331169280, 319987007488, 1919922028544, 11519532138496, 69117192765440, 414703156461568, 2488218938507264

Offset: 1

Author

R. H. Hardin, Mar 31 2018

Keywords

• nonn

Comments

Column 3 of A302069.

Examples

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

Links

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

Crossrefs

Cf. A302069.

Formula

Empirical: a(n) = 8*a(n-1) - 12*a(n-2) for n>3.