A297757 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1s.

1, 12, 52, 186, 1045, 5685, 28565, 148681, 783104, 4082179, 21289432, 111293510, 581390557, 3036127779, 15859365566, 82842802213, 432710054944, 2260195540670, 11805906967573, 61666590418664, 322107101630217, 1682485627292574

Offset: 1

Author

R. H. Hardin, Jan 05 2018

Keywords

• nonn

Comments

Column 3 of A297762.

Examples

			Some solutions for n=7
..1..1..0. .0..1..1. .0..1..1. .1..1..0. .0..1..0. .0..1..1. .1..1..1
..1..1..1. .1..1..0. .1..1..0. .1..1..0. .1..1..1. .0..1..1. .0..1..0
..0..1..0. .1..1..0. .0..1..1. .0..1..1. .0..1..0. .0..1..1. .0..1..0
..0..0..0. .0..1..0. .0..1..1. .0..0..0. .1..1..1. .0..0..0. .1..0..1
..0..1..0. .1..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .1..1..0
..1..1..1. .1..1..1. .0..1..1. .1..1..1. .1..1..1. .1..1..1. .0..1..1
..0..1..0. .0..0..0. .1..1..1. .0..0..0. .1..1..1. .1..1..0. .1..1..0
		

Links

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

Crossrefs

Cf. A297762.

Formula

Empirical: a(n) = 3*a(n-1) +2*a(n-2) +52*a(n-3) +2*a(n-4) +27*a(n-5) -378*a(n-6) -365*a(n-7) -173*a(n-8) +386*a(n-9) +1006*a(n-10) +488*a(n-11) +468*a(n-12) +328*a(n-13) -120*a(n-14) -80*a(n-15)