A283574 Number of 3Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.

0, 16, 169, 674, 4313, 21186, 104464, 513458, 2431143, 11478378, 53471911, 246887096, 1132514276, 5160569268, 23395062541, 105570183858, 474452680669, 2124725208078, 9484785230640, 42219767106150, 187451695326747

Offset: 1

Author

R. H. Hardin, Mar 11 2017

Keywords

• nonn

Comments

Row 3 of A283572.

Examples

			Some solutions for n=4
..1..1..0..1. .0..1..0..0. .0..1..1..0. .0..0..0..0. .1..0..1..0
..1..0..0..0. .0..1..0..0. .1..0..0..0. .0..1..1..0. .1..0..0..1
..0..0..1..0. .1..1..0..1. .1..0..1..0. .0..1..0..1. .1..0..1..0
		

Links

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

Crossrefs

Cf. A283572.

Formula

Empirical: a(n) = 4*a(n-1) +10*a(n-2) -6*a(n-3) -105*a(n-4) -108*a(n-5) -85*a(n-6) -14*a(n-7) -250*a(n-8) +176*a(n-9) -145*a(n-10) +44*a(n-11) -4*a(n-12)