%I
%S 4,3,8,9,21,42,81,165,330,657,1317,2634,5265,10533,21066,42129,84261,
%T 168522,337041,674085,1348170,2696337,5392677,10785354,21570705,
%U 43141413,86282826,172565649,345131301,690262602,1380525201,2761050405,5522100810
%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 6, 7 or 8 king-move adjacent elements, with upper left element zero.
%C Column 3 of A316693.
%H R. H. Hardin, <a href="/A316688/b316688.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) +a(n-2) +2*a(n-3) for n>6
%e Some solutions for n=5
%e ..0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0
%e ..0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0
%e ..0..1..0. .0..1..0. .1..0..1. .0..0..0. .0..0..0. .0..1..0. .0..0..0
%e ..0..0..0. .0..1..0. .1..1..1. .0..1..0. .0..1..0. .1..0..1. .0..1..0
%e ..0..0..0. .0..0..0. .1..1..1. .1..0..0. .1..0..0. .1..1..1. .0..0..1
%Y Cf. A316693.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jul 10 2018
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