A269286 Number of n X 5 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three no more than once.

756, 164556, 27788292, 4204943820, 598478857956, 81907569617580, 10908770041709316, 1424067311317705740, 183070424003703987492, 23250470194285817181804, 2923940806264087088770116

Offset: 1

Author

R. H. Hardin, Feb 21 2016

Keywords

• nonn

Examples

			Some solutions for n=2:
..0..3..3..1..0. .2..2..0..0..1. .3..1..0..3..2. .0..1..0..1..2
..2..2..0..1..3. .1..0..2..3..2. .3..1..3..2..3. .1..1..1..3..3
		

Links

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

Crossrefs

Column 5 of A269289.

Formula

Empirical: a(n) = 234*a(n-1) - 14277*a(n-2) + 68796*a(n-3) - 86436*a(n-4).

Empirical g.f.: 252*x*(3 - 49*x + 300*x^2 - 636*x^3) / (1 - 117*x + 294*x^2)^2. - Colin Barker, Jan 21 2019