%I #4 Mar 27 2018 10:10:58
%S 2,8,25,68,177,457,1183,3075,8018,20947,54782,143348,375200,982178,
%T 2571247,6731462,17623023,46137475,120789253,316230117,827900912,
%U 2167472413,5674516100,14856075638,38893710542,101825055692,266581456213
%N Number of nX4 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.
%C Column 4 of A301823.
%H R. H. Hardin, <a href="/A301819/b301819.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) -13*a(n-2) +13*a(n-3) -6*a(n-4) +a(n-5)
%e Some solutions for n=5
%e ..0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1
%e ..1..1..0..0. .0..1..0..0. .0..1..0..1. .0..0..0..0. .0..0..1..1
%e ..0..0..1..1. .1..0..1..1. .1..0..1..0. .1..1..0..1. .0..0..1..0
%e ..1..1..0..1. .0..1..0..0. .0..1..0..1. .1..0..1..1. .1..1..0..1
%e ..0..0..1..1. .1..0..1..1. .1..0..1..1. .0..0..0..0. .0..0..1..1
%Y Cf. A301823.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 27 2018
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