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A221884 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction.

%I A221884 #6 Jul 23 2025 02:17:53
%S A221884 6,326,11878,449069,16834526,632170065,23731120064,890904857988,
%T A221884 33445557232807,1255586659165355,47136215887025325,
%U A221884 1769549765701234779,66431007429900317322,2493899211740460190981,93623949326949457663958
%N A221884 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without consecutive moves in the same direction.
%C A221884 Column 3 of A221886
%H A221884 R. H. Hardin, <a href="/A221884/b221884.txt">Table of n, a(n) for n = 1..66</a>
%e A221884 Some solutions for n=3
%e A221884 ..0..2..2....0..2..1....1..2..2....0..2..2....2..0..2....0..3..0....0..4..1
%e A221884 ..1..3..0....0..1..0....1..1..0....1..0..1....0..2..0....3..0..1....1..1..0
%e A221884 ..0..1..0....3..1..1....0..2..0....2..1..0....0..1..2....0..0..2....0..0..2
%K A221884 nonn
%O A221884 1,1
%A A221884 _R. H. Hardin_ Jan 30 2013