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%I #6 Apr 30 2022 20:57:50
%S 8,49,46,84,133,221,406,743,1327,2396,4385,8003,14556,26527,48421,
%T 88330,161061,293777,535950,977643,1783259,3252908,5933861,10824167,
%U 19744652,36017043,65700297,119846482,218616585,398787421,727444438,1326960543
%N Number of n X 4 0..1 arrays with every element unequal to 0, 1, 2 or 3 king-move adjacent elements, with upper left element zero.
%C Column 4 of A303727.
%H R. H. Hardin, <a href="/A303723/b303723.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) -a(n-5) -2*a(n-6) for n>8.
%e Some solutions for n=5
%e ..0..1..1..1. .0..0..0..0. .0..1..1..1. .0..1..1..1. .0..1..1..1
%e ..0..1..1..1. .0..0..0..0. .1..1..1..0. .1..1..1..1. .1..1..1..1
%e ..0..1..1..1. .0..0..0..0. .1..1..0..0. .1..1..1..0. .1..1..1..1
%e ..0..1..1..1. .0..0..0..1. .1..0..0..0. .1..1..0..0. .1..1..1..0
%e ..0..1..1..0. .1..0..1..1. .0..0..0..0. .1..0..0..0. .0..1..0..0
%Y Cf. A303727.
%K nonn
%O 1,1
%A _R. H. Hardin_, Apr 29 2018
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