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%I #5 Mar 31 2012 12:37:30
%S 451762,140274002,41170011836,12365282426546,3690894707522275,
%T 1105092894348108870,330369121707817687620,98846625956052689351148,
%U 29561564907274388361999040,8843044595935413687485979415
%N 1/4 the number of (n+1)X7 0..3 arrays with every 2X2 subblock having distinct clockwise edge differences
%C Column 6 of A209716
%H R. H. Hardin, <a href="/A209714/b209714.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=4
%e ..3..2..1..2..0..3..2....2..0..2..1..3..3..2....0..0..3..0..0..1..1
%e ..3..0..2..0..1..1..3....0..3..0..2..1..0..2....1..3..1..3..2..0..3
%e ..3..1..3..1..3..0..3....2..2..2..1..3..0..3....2..1..2..1..3..0..1
%e ..0..1..0..1..0..2..2....0..3..0..2..1..1..3....1..3..1..3..2..2..3
%e ..0..3..0..3..0..3..0....1..0..2..1..3..0..1....0..3..0..0..3..0..3
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 11 2012