A297871 Number of nX3 0..1 arrays with every element equal to 2, 3 or 5 king-move adjacent elements, with upper left element zero.

0, 3, 0, 3, 0, 3, 6, 23, 68, 205, 572, 1553, 4208, 11405, 30988, 84553, 231176, 632915, 1734004, 4751591, 13021550, 35685855, 97797264, 268015939, 734511376, 2012982445, 5516772882, 15119337301, 41436399090, 113561805901, 311231201784

Offset: 1

Author

R. H. Hardin, Jan 07 2018

Keywords

• nonn

Comments

Column 3 of A297876.

Examples

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

Links

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

Crossrefs

Cf. A297876.

Formula

Empirical: a(n) = 2*a(n-1) +5*a(n-2) -3*a(n-3) -15*a(n-4) -9*a(n-5) +24*a(n-6) +29*a(n-7) -a(n-8) -36*a(n-9) -67*a(n-10) -23*a(n-11) +49*a(n-12) +43*a(n-13) +14*a(n-14) +3*a(n-15) -4*a(n-16) -2*a(n-17) for n>18