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%I #5 Dec 18 2015 18:18:25
%S 0,4,30,58081,78633756,4919350997521,720107530988047980,
%T 2283974100099963226425600
%N Number of n X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2
%C Diagonal of A221255
%e Some solutions for n=3
%e ..0..2..0....1..2..0....0..2..0....1..2..0....0..2..1....1..2..1....0..2..1
%e ..2..2..0....1..2..0....1..2..0....0..2..1....1..2..0....0..2..0....1..2..1
%e ..1..2..0....1..2..0....2..2..0....1..2..0....1..2..0....0..2..1....0..2..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 06 2013