A298050 Number of nX3 0..1 arrays with every element equal to 1, 2, 4 or 6 king-move adjacent elements, with upper left element zero.

1, 7, 15, 19, 23, 34, 63, 96, 147, 233, 368, 588, 933, 1500, 2404, 3842, 6157, 9887, 15907, 25577, 41128, 66175, 106524, 171543, 276293, 445096, 717116, 1155533, 1862256, 3001558, 4838268, 7799411, 12573667, 20271639, 32684289, 52699948

Offset: 1

Author

R. H. Hardin, Jan 11 2018

Keywords

• nonn

Comments

Column 3 of A298055.

Examples

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

Links

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

Crossrefs

Cf. A298055.

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) -2*a(n-3) -3*a(n-5) +3*a(n-6) +3*a(n-7) -a(n-8) +2*a(n-9) +6*a(n-10) -8*a(n-11) -3*a(n-12) -4*a(n-13) -2*a(n-14) +4*a(n-15) +8*a(n-16) -a(n-17) -3*a(n-18) for n>19