A221342 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2

7, 137, 2856, 60807, 1299057, 27767394, 593562702, 12688126159, 271223239234, 5797699341153, 123932233563380, 2649188126866350, 56629314186026164, 1210513943745878094, 25876068208481143920, 553129442930337241907

Offset

1,1

Comments

Column 3 of A221345

Links

R. H. Hardin, Table of n, a(n) for n = 1..121

Formula

Empirical: a(n) = 43*a(n-1) -604*a(n-2) +3305*a(n-3) -5534*a(n-4) -8103*a(n-5) +18838*a(n-6) +17434*a(n-7) -4723*a(n-8) -11537*a(n-9) -7289*a(n-10) -2900*a(n-11) -652*a(n-12) -296*a(n-13) -94*a(n-14) -16*a(n-15)

Example

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

Crossrefs

Sequence in context: A051504 A058881 A100520 * A221298 A009701 A120052

Adjacent sequences: A221339 A221340 A221341 * A221343 A221344 A221345

Keyword

nonn

Author

R. H. Hardin Jan 11 2013

Status

approved