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%I #5 Mar 31 2012 12:37:29
%S 24,2710,1277340,2744311427,26024000948100,1105092894348108870,
%T 208427296314737259382008,175434641568425738606430293927
%N 1/4 the number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having distinct clockwise edge differences
%C Diagonal of A209716
%e Some solutions for n=4
%e ..0..2..0..1..2....1..0..3..3..0....3..3..2..3..0....0..2..1..1..0
%e ..1..3..0..3..1....1..3..1..0..2....0..1..3..0..2....2..1..3..0..2
%e ..3..2..2..0..3....3..2..3..2..1....2..0..2..2..1....0..2..1..1..0
%e ..2..0..3..0..1....1..0..0..0..2....1..2..3..0..2....2..1..3..0..2
%e ..1..2..2..2..0....3..1..3..2..1....2..0..1..0..3....1..3..2..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 11 2012