%I #5 Mar 31 2012 12:36:36

%S 2,60,1265,29229,658770,15066222,342328663,7797114144,177447181083,

%T 4039488090307,91947444344704,2092999963213610,47642308975551650,

%U 1084472533833020100,24685590900071146822,561912613968766782369

%N Number of nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors

%C Column 4 of A199647

%H R. H. Hardin, <a href="/A199643/b199643.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for n=3

%e ..0..1..1..2....0..1..1..0....0..0..0..0....0..0..1..1....0..0..0..1

%e ..0..1..1..2....0..1..2..0....0..1..1..1....2..2..2..1....1..2..2..1

%e ..2..2..2..2....0..0..2..2....2..2..2..2....2..1..1..1....1..1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Nov 08 2011