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Half the number of nX4 binary arrays with the number of 1-1 horizontal, vertical, diagonal and antidiagonal adjacencies equal to the number of 0-0 adjacencies
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%I #5 Mar 31 2012 12:35:50

%S 2,18,180,2184,28440,385316,5358022,75912216,1090973732,15858156696,

%T 232676544078,3440947655952,51232791119120,767336873453826,

%U 11552848716881830,174745834818648930,2654168057004043584

%N Half the number of nX4 binary arrays with the number of 1-1 horizontal, vertical, diagonal and antidiagonal adjacencies equal to the number of 0-0 adjacencies

%C Column 4 of A183289

%H R. H. Hardin, <a href="/A183285/b183285.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for 4X4 with a(1,1)=0

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 03 2011