A302011 Number of 4 X n 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, 369040, 5276816, 75450768, 1078839952, 15425887120, 220568403088, 3153816694160, 45095125134992, 644796609413008, 9219680980164752, 131828418659815824, 1884960228421653136

Offset: 1

Author

R. H. Hardin, Mar 30 2018

Keywords

• nonn

Comments

Row 4 of A302010.

Examples

			Some solutions for n=5
..0..0..1..0..0. .0..0..1..0..0. .0..1..0..0..1. .0..1..1..1..0
..0..1..0..1..1. .0..0..1..1..0. .0..1..0..0..0. .0..1..0..1..0
..0..1..0..1..1. .0..0..0..0..1. .0..0..1..0..1. .0..1..1..1..1
..1..0..1..0..1. .0..1..0..0..0. .0..0..1..0..0. .0..0..1..0..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) +20*a(n-2) -16*a(n-3) -64*a(n-4) for n > 6.