%I #6 Apr 23 2021 11:23:03
%S 3,9,13,31,79,168,430,1241,3577,10976,35220,115104,382846,1287463,
%T 4355297,14794917,50378019,171779607,586281739,2002004862,6838403076,
%U 23363178277,79828543393,272780054792,932149927652,3185441895514
%N Number of n X 3 0..1 arrays with every element unequal to 0, 1, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.
%C Column 3 of A305649.
%H R. H. Hardin, <a href="/A305644/b305644.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) -7*a(n-2) +17*a(n-3) -52*a(n-4) +50*a(n-5) -48*a(n-6) +92*a(n-7) -45*a(n-8) -17*a(n-9) +68*a(n-10) -44*a(n-11) -5*a(n-12) -127*a(n-13) +174*a(n-14) -54*a(n-15) -16*a(n-16) +8*a(n-17) for n>19
%e Some solutions for n=5
%e ..0..0..0. .0..0..0. .0..0..1. .0..1..0. .0..0..0. .0..1..1. .0..1..1
%e ..0..0..0. .0..0..0. .0..1..1. .0..0..0. .0..0..0. .1..1..1. .0..0..1
%e ..0..0..0. .0..0..1. .0..0..0. .0..0..0. .0..0..0. .1..1..1. .0..0..0
%e ..1..0..0. .0..0..0. .0..0..1. .0..0..1. .0..0..1. .0..1..1. .0..0..0
%e ..0..0..0. .0..0..0. .0..1..1. .0..1..1. .0..1..1. .0..0..1. .0..0..1
%Y Cf. A305649.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jun 07 2018
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