A304266 Number of nX4 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.

5, 5, 10, 21, 50, 116, 259, 601, 1397, 3196, 7359, 17016, 39172, 90185, 208017, 479413, 1104402, 2545521, 5866934, 13519272, 31155923, 71803941, 165473389, 381338852, 878829251, 2025313404, 4667430712, 10756397233, 24788787493, 57127147381

Offset: 1

Author

R. H. Hardin, May 09 2018

Keywords

• nonn

Comments

Column 4 of A304270.

Examples

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

Links

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

Crossrefs

Cf. A304270.

Formula

Empirical: a(n) = a(n-1) +a(n-2) +5*a(n-3) +a(n-4) -3*a(n-5) -3*a(n-6) for n>7