A221224 Number of n X 3 arrays of occupancy after each element stays put or moves to some king-move neighbor.

8, 400, 18768, 867776, 39983152, 1840507104, 84698310960, 3897368193376, 179330419695472, 8251471025928064, 379670549581978384, 17469551012762540960, 803815384904102897232, 36985439805161039680544

Offset

1,1

Comments

Column 3 of A221225.

Links

R. H. Hardin, Table of n, a(n) for n = 1..23

Formula

Empirical: a(n) = 77*a(n-1) - 1710*a(n-2) + 13925*a(n-3) - 39617*a(n-4) + 25616*a(n-5) - 5184*a(n-6).

Empirical g.f.: 8*x*(1 - 27*x + 206*x^2 - 595*x^3 + 577*x^4 - 146*x^5) / (1 - 77*x + 1710*x^2 - 13925*x^3 + 39617*x^4 - 25616*x^5 + 5184*x^6). - Colin Barker, Aug 04 2018

Example

Some solutions for n=3:
..0..2..0....1..1..0....1..0..0....0..1..0....2..1..3....1..0..1....0..1..4
..0..4..0....1..4..0....1..5..1....1..1..3....0..0..1....0..1..1....1..1..0
..0..1..2....1..0..1....0..1..0....0..2..1....0..1..1....1..2..2....0..0..2

Crossrefs

Cf. A221225.

Sequence in context: A165036 A185254 A347997 * A281439 A220550 A191874

Adjacent sequences: A221221 A221222 A221223 * A221225 A221226 A221227

Keyword

nonn

Author

R. H. Hardin, Jan 05 2013

Status

approved