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A221224
Number of n X 3 arrays of occupancy after each element stays put or moves to some king-move neighbor.
1
8, 400, 18768, 867776, 39983152, 1840507104, 84698310960, 3897368193376, 179330419695472, 8251471025928064, 379670549581978384, 17469551012762540960, 803815384904102897232, 36985439805161039680544
OFFSET
1,1
COMMENTS
Column 3 of A221225.
LINKS
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2013
STATUS
approved