%I
%S 0,212,19540,1972288,277234340,47309058644,5589659640640,
%T 870640738340900,123996249589648356,17750283049298827840,
%U 2576653369311868344772,370733913903692365171892,53509487787359717704828880
%N Number of nX6 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 6 of A204301
%H R. H. Hardin, <a href="/A204299/b204299.txt">Table of n, a(n) for n = 1..30</a>
%e Some solutions for n=3
%e ..2..1..1..0..0..3....0..0..1..1..1..2....0..1..2..0..0..1....0..1..0..2..1..0
%e ..0..0..1..2..1..1....1..1..2..0..0..0....0..1..1..1..0..1....0..1..0..2..1..0
%e ..1..1..1..0..0..0....3..0..0..1..1..1....2..1..0..0..0..1....2..1..0..0..1..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 14 2012
|