%I #5 Mar 31 2012 12:35:50
%S 2,18,164,2101,29100,417190,6104168,90554742,1356933444,20489622108,
%T 311268434796,4751843588209,72836045462648,1120231330154058,
%U 17279391496374040,267199601139845596,4140858845912841972
%N Half the number of nX4 binary arrays with the number of 1-1 adjacencies equal to the number of 0-0 adjacencies
%C Column 4 of A183253
%H R. H. Hardin, <a href="/A183250/b183250.txt">Table of n, a(n) for n = 1..100</a>
%e Some solutions with a(1,1)=0 for 3X4
%e ..0..1..1..0....0..1..1..0....0..0..1..0....0..0..0..0....0..0..1..0
%e ..0..1..1..0....0..0..0..1....1..1..1..0....1..1..0..0....1..1..0..0
%e ..0..1..0..0....1..1..1..0....0..0..1..0....1..1..1..1....1..0..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 03 2011