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%I #7 Sep 17 2018 08:32:19
%S 2,20,140,863,4962,27313,145932,763031,3924694,19928429,100145056,
%T 498967875,2468341930,12136538329,59362244596,289033801519,
%U 1401690320766,6773621702213,32630424771912,156746889564187,751052250017618
%N Number of defective 3-colorings of an n X 3 0..2 array connected horizontally and vertically with exactly one mistake and colors introduced in row-major 0..2 order.
%H R. H. Hardin, <a href="/A229454/b229454.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4).
%F Empirical g.f.: x*(2 - 2*x^2 + 3*x^3) / (1 - 5*x + 2*x^2)^2. - _Colin Barker_, Sep 17 2018
%e Some solutions for n=3:
%e ..0..0..1....0..1..0....0..1..2....0..1..0....0..1..2....0..1..2....0..1..0
%e ..2..1..0....0..2..1....2..0..1....1..0..1....1..2..1....2..2..0....2..1..2
%e ..1..0..2....2..1..0....1..2..1....0..2..2....2..0..0....1..0..2....1..0..1
%Y Column 3 of A229460.
%K nonn
%O 1,1
%A _R. H. Hardin_, Sep 24 2013
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