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%I #4 Aug 24 2018 11:01:39
%S 4,10,20,36,76,160,344,748,1624,3544,7724,16856,36776,80252,175128,
%T 382168,833996,1819992,3971720,8667356,18914520,41276600,90076716,
%U 196571800,428972904,936135100,2042900376,4458162072,9728917388
%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Column 3 of A318343.
%H R. H. Hardin, <a href="/A318338/b318338.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +2*a(n-2) -3*a(n-3) -2*a(n-4) +2*a(n-5) for n>6
%e Some solutions for n=5
%e ..0..1..1. .0..0..1. .0..0..0. .0..1..1. .0..1..1. .0..0..0. .0..0..0
%e ..1..1..1. .0..0..1. .0..0..0. .1..1..1. .1..1..1. .0..0..0. .0..0..0
%e ..0..0..0. .0..0..1. .0..0..0. .1..1..1. .0..0..0. .1..1..1. .0..0..0
%e ..0..0..1. .0..0..1. .1..1..1. .1..1..0. .0..0..0. .1..1..1. .1..1..1
%e ..0..1..1. .0..0..1. .1..1..0. .1..0..0. .0..0..0. .1..1..1. .1..1..1
%Y Cf. A318343.
%K nonn
%O 1,1
%A _R. H. Hardin_, Aug 24 2018
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