%I #5 Mar 31 2012 12:37:01
%S 0,16,160,5956,56104,1972288,38262132,826746944,19525910056,
%T 432375489440,9706792686848,218843084884500,4924743527802436,
%U 110797467340650548,2494225116607793984,56147370697399654912,1263637381614193741120
%N Number of nX4 0..3 arrays with every element neighboring horizontally or vertically both a 0 and a 1, and 2 introduced before 3 in row major order
%C Column 4 of A204301
%H R. H. Hardin, <a href="/A204297/b204297.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=5
%e ..2..1..1..0....1..0..0..1....1..1..1..2....1..1..0..2....0..1..1..0
%e ..0..0..1..0....1..0..0..1....0..0..0..0....0..0..0..1....0..1..1..0
%e ..1..0..1..2....2..3..0..1....0..0..1..1....1..2..3..1....0..1..2..3
%e ..1..2..1..0....0..1..3..0....1..2..0..1....1..3..0..0....1..3..0..1
%e ..0..0..1..0....0..1..1..0....1..0..0..1....0..0..1..1....1..0..0..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 14 2012
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