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%I A301664 #4 Mar 25 2018 11:35:06
%S A301664 1,10,30,118,407,1498,5289,19184,68832,247756,890523,3203084,11517675,
%T A301664 41422044,148957388,535680672,1926390947,6927645818,24912983963,
%U A301664 89591402294,322185988646,1158636174394,4166654317703,14984004032116
%N A301664 Number of nX3 0..1 arrays with every element equal to 1, 2 or 4 horizontally or vertically adjacent elements, with upper left element zero.
%C A301664 Column 3 of A301669.
%H A301664 R. H. Hardin, <a href="/A301664/b301664.txt">Table of n, a(n) for n = 1..210</a>
%F A301664 Empirical: a(n) = 2*a(n-1) +6*a(n-2) -2*a(n-4) +2*a(n-5) -9*a(n-6) -50*a(n-7) -37*a(n-8) +34*a(n-9) +43*a(n-10) -16*a(n-11) +15*a(n-12) +18*a(n-13) -7*a(n-14) -2*a(n-16) +4*a(n-17) -6*a(n-18) +a(n-20)
%e A301664 Some solutions for n=5
%e A301664 ..0..0..0. .0..1..1. .0..0..1. .0..0..0. .0..0..0. .0..0..1. .0..0..1
%e A301664 ..1..1..1. .0..0..0. .0..1..1. .0..1..0. .0..1..0. .1..1..1. .1..1..1
%e A301664 ..1..0..1. .1..1..0. .1..1..0. .0..1..0. .0..1..1. .1..0..0. .1..0..0
%e A301664 ..0..0..1. .1..0..1. .0..0..0. .1..1..0. .1..0..0. .1..1..0. .1..0..1
%e A301664 ..1..1..1. .0..0..1. .0..1..1. .0..0..0. .1..1..0. .0..0..0. .1..0..1
%Y A301664 Cf. A301669.
%K A301664 nonn
%O A301664 1,2
%A A301664 _R. H. Hardin_, Mar 25 2018

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