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%I #4 Mar 03 2018 08:29:14
%S 1,6,9,26,57,133,306,709,1642,3805,8811,20409,47276,109514,253686,
%T 587661,1361316,3153496,7305099,16922333,39200767,90809027,210360189,
%U 487301922,1128840861,2614973750,6057619008,14032549467,32506574899,75301884294
%N Number of nX3 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Column 3 of A300350.
%H R. H. Hardin, <a href="/A300345/b300345.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +a(n-2) -2*a(n-5) -2*a(n-6) -2*a(n-7) -a(n-8) for n>10
%e Some solutions for n=5
%e ..0..1..1. .0..0..0. .0..0..0. .0..1..0. .0..0..1. .0..1..0. .0..0..0
%e ..0..0..0. .1..1..0. .1..1..1. .0..1..0. .0..1..0. .0..1..0. .1..1..0
%e ..1..1..0. .0..1..0. .0..0..1. .1..0..1. .1..0..1. .0..1..0. .0..1..0
%e ..1..0..1. .0..1..1. .1..0..1. .1..0..1. .0..1..0. .1..0..1. .0..1..0
%e ..0..1..1. .0..0..1. .1..0..0. .1..0..1. .0..1..0. .1..0..1. .0..1..1
%Y Cf. A300350.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 03 2018
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