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%I #12 Dec 18 2015 18:18:13
%S 0,9,1472,2572816,48909857500,10211121295308649,
%T 23397344246732649325860
%N Number of n X n arrays of occupancy after each element moves to some horizontal or vertical neighbor.
%C Diagonal of A217273
%e Some solutions for n=3
%e ..1..1..2....2..1..1....0..0..1....2..1..1....0..2..1....0..1..2....1..1..0
%e ..1..0..2....2..1..0....3..1..2....1..0..1....1..0..1....1..1..3....1..0..0
%e ..1..1..0....0..2..0....2..0..0....1..2..0....1..1..2....0..0..1....1..3..2
%K nonn,hard,more
%O 1,2
%A _R. H. Hardin_, Sep 29 2012