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%I #7 Oct 06 2015 21:52:43
%S 152,33416,43689232,343092183768,16261866249456960,
%T 4664832940178290442768,8112174131718066295245481744,
%U 85615997981426512072932676873435656
%N Number of (n+1) X (n+1) 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to the number of counterclockwise edge increases.
%C Diagonal of A208492.
%e Some solutions for n=4:
%e ..1..0..3..2..1....3..1..0..0..1....1..2..0..2..2....1..0..2..0..1
%e ..2..1..0..3..2....1..1..1..0..0....1..1..3..0..2....2..1..3..1..0
%e ..2..2..1..0..3....3..1..3..1..0....0..0..1..3..0....1..3..2..3..1
%e ..3..2..1..1..0....0..3..3..3..2....1..0..0..2..3....2..0..3..1..0
%e ..1..3..2..1..0....1..0..3..0..3....1..1..1..3..3....1..2..0..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 27 2012
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