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Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..1 4Xn array
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%I #3 Dec 13 2012 17:44:18

%S 1,78,720,10989,128448,1701214,20736643,263993960

%N Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..1 4Xn array

%C Row 4 of A220406

%e Some solutions for n=3

%e ..1..0..0....0..0..1....0..1..0....1..0..1....0..1..0....1..0..1....0..1..1

%e ..0..0..0....0..0..0....0..1..0....1..0..0....1..0..1....1..0..1....1..0..0

%e ..0..0..0....0..0..1....0..0..0....0..0..1....0..0..0....1..0..1....1..0..0

%e ..0..0..1....0..0..0....1..1..1....1..0..1....1..1..1....0..0..1....1..1..0

%K nonn

%O 1,2

%A _R. H. Hardin_ Dec 13 2012