A298254 Number of nX3 0..1 arrays with every element equal to 2, 3, 5 or 8 king-move adjacent elements, with upper left element zero.

0, 3, 1, 4, 3, 7, 14, 35, 89, 242, 643, 1713, 4584, 12341, 33393, 90828, 247775, 677335, 1853786, 5076655, 13907485, 38106762, 104424087, 286173877, 784293860, 2149515757, 5891305033, 16146865524, 44255648343, 121297428367, 332457355358

Offset: 1

Author

R. H. Hardin, Jan 15 2018

Keywords

• nonn

Comments

Column 3 of A298259.

Examples

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

Links

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

Crossrefs

Cf. A298259.

Formula

Empirical: a(n) = 3*a(n-1) +3*a(n-2) -7*a(n-3) -14*a(n-4) +2*a(n-5) +34*a(n-6) +16*a(n-7) -20*a(n-8) -48*a(n-9) -50*a(n-10) +36*a(n-11) +89*a(n-12) +39*a(n-13) +3*a(n-14) -9*a(n-15) -14*a(n-16) +2*a(n-18) for n>19