%I #10 Jun 16 2017 05:29:02
%S 0,288,4032,50112,575424,6298560,66764736,691581888,7040530368,
%T 70711413696,702522486720,6917780251584,67615723104192,
%U 656742815497152,6344497107509184,61004779879896000,584181772129884096
%N Number of defective 3-colorings of an n X 4 0..2 array connected diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.
%C Column 4 of A229510
%H R. H. Hardin, <a href="/A229506/b229506.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 18*a(n-1) - 81*a(n-2) for n>4.
%F Conjectures from _Colin Barker_, Jun 16 2017: (Start)
%F G.f.: 288*x^2*(1 - x)*(1 - 3*x) / (1 - 9*x)^2.
%F a(n) = 64*3^(2*n-5)*(8*n - 3) for n>2.
%F (End)
%e Some solutions for n=3
%e ..0..1..1..1....0..0..0..0....0..0..0..0....0..1..2..2....0..0..1..2
%e ..0..1..0..2....1..2..1..2....1..2..1..2....0..1..0..2....2..2..2..2
%e ..0..1..0..1....0..0..1..1....1..0..1..1....2..2..0..1....0..0..1..0
%K nonn
%O 1,2
%A _R. H. Hardin_, Sep 25 2013