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%I #7 Dec 11 2015 11:50:44
%S 256,6668,2761756,5465582068,51845281856116,2363085244017636372,
%T 518342328616619031217028,547728179121316322465056282220
%N Number of (n+1) X (n+1) 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly three counterclockwise and three clockwise edge increases.
%C Diagonal of A206137.
%e Some solutions for n=4:
%e ..1..2..3..1..2....0..1..2..1..2....2..1..2..3..0....3..1..3..2..3
%e ..2..3..1..2..0....1..2..0..2..1....0..2..0..1..2....0..2..0..3..2
%e ..1..2..3..0..2....0..1..2..1..3....1..3..2..3..0....1..3..1..0..3
%e ..0..1..2..3..0....2..3..0..2..0....3..2..0..1..2....2..0..2..1..0
%e ..3..0..1..2..3....1..2..3..1..2....1..3..1..2..1....3..1..3..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 04 2012
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