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%I #5 Mar 31 2012 12:37:30
%S 25,2829,1386131,3111914707,31192434742293,1413503057063618368,
%T 287490532338602681041344,263539796114390477346345246841
%N 1/4 the number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having one or four distinct clockwise edge differences
%C Diagonal of A209858
%e Some solutions for n=4
%e ..3..0..3..3..0....0..2..2..1..2....1..1..1..3..2....2..1..0..1..0
%e ..0..1..3..3..2....2..3..0..2..0....3..0..3..0..0....1..3..0..3..0
%e ..1..3..2..0..2....3..1..1..3..0....0..1..1..3..1....0..0..1..3..1
%e ..1..0..3..2..1....2..0..3..0..1....2..0..3..2..0....3..1..3..2..0
%e ..3..3..1..0..2....2..3..1..3..1....3..3..1..3..0....1..2..1..3..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 14 2012