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%I #5 Mar 31 2012 12:36:34
%S 3,177,26704,13048509,22496409154
%N Number of 2nX2n 0..2 arrays with values 0..2 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors
%C Diagonal of A198452
%e Some solutions for n=3
%e ..0..1..2..1..0..1....0..1..1..0..1..2....0..1..1..2..1..2....0..1..1..2..2..1
%e ..1..1..2..1..0..2....2..0..0..0..1..0....2..0..0..2..1..0....1..2..2..0..0..2
%e ..0..0..2..1..0..2....2..0..1..1..1..0....2..0..0..2..1..0....1..2..2..0..0..2
%e ..1..0..2..1..0..0....0..0..1..0..0..2....0..1..1..2..1..1....0..0..0..2..2..1
%e ..1..0..2..1..1..1....2..2..1..0..0..2....0..1..1..2..2..2....2..2..0..2..2..1
%e ..2..0..2..0..0..2....0..2..1..2..2..0....1..0..0..1..1..0....1..2..0..1..1..2
%K nonn
%O 1,1
%A _R. H. Hardin_ Oct 25 2011