A220998 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor.

8, 306, 11017, 394580, 14113081, 504635391, 18042682111, 645084293748, 23063745428252, 824598809224499, 29481898439700635, 1054066854447577743, 37686070858394633616, 1347390750744270331311, 48173285030655948141067

Offset: 1

Author

R. H. Hardin Dec 28 2012

Keywords

• nonn

Comments

Column 3 of A221001

Examples

			Some solutions for n=3
..0..3..0....0..4..0....0..3..1....0..2..2....1..2..0....0..3..0....1..2..2
..3..2..1....1..1..0....3..0..0....0..1..1....2..2..0....2..1..1....1..0..1
..0..0..0....1..0..2....1..0..1....0..2..1....0..0..2....2..0..0....2..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..29

Formula

Empirical: a(n) = 45*a(n-1) -327*a(n-2) -189*a(n-3) +2183*a(n-4) -1362*a(n-5) +976*a(n-6) +10221*a(n-7) +3837*a(n-8) -432*a(n-9) -11*a(n-10)