A269292 Number of 4Xn 0..3 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling three no more than once.

256, 29160, 1698732, 87559668, 4204943820, 193446959076, 8642330207532, 377958654569412, 16263720330382476, 690974658284107428, 29056221832723692012, 1211537520551702429316, 50159175757694154381132

Offset: 1

Author

R. H. Hardin, Feb 21 2016

Keywords

• nonn

Comments

Row 4 of A269289.

Examples

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

Links

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

Crossrefs

Cf. A269289.

Formula

Empirical: a(n) = 96*a(n-1) -3108*a(n-2) +40720*a(n-3) -265326*a(n-4) +931200*a(n-5) -1766452*a(n-6) +1678992*a(n-7) -622521*a(n-8) for n>12