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Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 king-move adjacent elements, with upper left element zero.
2

%I #4 Jan 15 2018 08:05:40

%S 4,13,20,40,89,195,451,1046,2453,5810,13796,32903,78633,188163,450830,

%T 1080857,2592672,6221496,14932953,35849159,86073611,206681378,

%U 496321653,1191918914,2862503060,6874749395,16511107561,39655346739,95242735994

%N Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 king-move adjacent elements, with upper left element zero.

%C Column 3 of A298221.

%H R. H. Hardin, <a href="/A298216/b298216.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +a(n-3) -13*a(n-4) +3*a(n-5) -a(n-6) +18*a(n-7) -4*a(n-8) +7*a(n-9) -7*a(n-10) +5*a(n-11) -6*a(n-12) -a(n-13) -4*a(n-14) for n>15

%e Some solutions for n=7

%e ..0..1..0. .0..1..0. .0..1..1. .0..1..1. .0..1..0. .0..1..0. .0..1..0

%e ..1..0..0. .0..0..0. .1..0..0. .0..1..0. .1..1..0. .0..1..1. .1..1..0

%e ..1..0..0. .1..1..1. .0..0..1. .1..0..1. .1..1..0. .0..1..1. .1..1..0

%e ..0..0..1. .0..0..0. .0..0..1. .0..0..1. .0..1..1. .1..1..0. .1..1..0

%e ..0..0..1. .1..1..1. .0..0..1. .0..0..1. .0..1..1. .1..1..0. .0..1..1

%e ..0..0..1. .0..0..0. .0..0..1. .0..0..1. .0..1..1. .1..1..0. .0..1..1

%e ..0..1..0. .0..1..0. .0..1..0. .1..0..1. .0..1..0. .0..1..0. .0..1..0

%Y Cf. A298221.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 15 2018