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%I #4 Jan 10 2018 07:33:15
%S 1,17,48,146,424,1274,3820,11529,34783,104826,315711,950990,2864947,
%T 8631274,26003209,78338270,236004118,710993764,2141965614,6452965003,
%U 19440438745,58566971613,176440981687,531552505076,1601374384608
%N Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.
%C Column 3 of A297993.
%H R. H. Hardin, <a href="/A297988/b297988.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) -a(n-2) +a(n-3) +6*a(n-4) +4*a(n-6) -2*a(n-8) -a(n-9) -2*a(n-10) -2*a(n-11) for n>13
%e Some solutions for n=7
%e ..0..0..0. .0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..0..0. .0..1..0
%e ..0..1..1. .1..0..1. .1..1..0. .1..0..0. .1..0..1. .1..1..1. .1..0..1
%e ..1..0..1. .1..0..1. .1..0..1. .1..0..1. .1..0..0. .0..0..0. .1..0..1
%e ..0..1..0. .0..0..1. .1..0..1. .1..1..1. .0..1..1. .1..1..0. .0..1..0
%e ..1..0..0. .1..1..0. .0..0..1. .1..0..1. .0..0..1. .1..0..1. .0..1..0
%e ..1..1..1. .0..1..0. .1..1..0. .0..0..1. .1..1..0. .0..1..0. .0..1..0
%e ..0..0..0. .0..0..1. .0..0..0. .1..1..1. .0..0..0. .0..1..0. .1..1..0
%Y Cf. A297993.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 10 2018
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