%I #4 May 27 2018 17:42:04
%S 4,21,24,54,108,236,509,1091,2363,5109,11034,23867,51606,111571,
%T 241263,521680,1128006,2439107,5274072,11404090,24659080,53320283,
%U 115294335,249300825,539062799,1165614674,2520407019,5449872468,11784251403
%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3 or 8 king-move adjacent elements, with upper left element zero.
%C Column 3 of A305230.
%H R. H. Hardin, <a href="/A305225/b305225.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +a(n-2) -3*a(n-4) -a(n-5) +2*a(n-6) for n>9
%e Some solutions for n=5
%e ..0..0..0. .0..0..1. .0..1..1. .0..0..0. .0..0..0. .0..0..0. .0..1..1
%e ..1..1..1. .0..0..0. .1..1..1. .0..0..0. .0..0..0. .0..0..0. .0..0..1
%e ..1..1..1. .0..1..0. .1..0..1. .0..0..0. .0..0..1. .0..0..0. .0..0..0
%e ..0..1..1. .0..0..0. .1..1..1. .0..1..0. .0..1..1. .1..1..1. .0..0..1
%e ..0..0..1. .0..0..1. .0..1..0. .0..0..0. .1..1..1. .1..1..1. .0..1..1
%Y Cf. A305230.
%K nonn
%O 1,1
%A _R. H. Hardin_, May 27 2018