%I #5 Mar 31 2012 12:36:35
%S 2,65,2453,125468,6235011,316561994,15958823113,806680624447,
%T 40736752748774,2057896226081573,103945296750116087,
%U 5250572116269762125,265216743260845702081,13396704712673136390007,676696655003807234547723
%N Number of nX4 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors
%C Column 4 of A199149
%H R. H. Hardin, <a href="/A199145/b199145.txt">Table of n, a(n) for n = 1..200</a>
%e Some solutions for n=3
%e ..0..0..1..1....0..0..1..1....0..1..1..1....0..1..0..0....0..0..1..1
%e ..2..2..2..3....1..2..3..1....0..2..3..0....0..1..0..2....0..0..2..2
%e ..0..0..3..3....1..2..3..3....0..2..3..0....1..1..2..2....2..2..0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Nov 03 2011
