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A297390 Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1.

%I A297390 #8 Feb 28 2019 07:44:16
%S A297390 3,9,19,57,139,369,963,2489,6523,16929,44147,114953,299307,779697,
%T A297390 2030243,5287833,13770971,35864001,93402579,243249193,633503627,
%U A297390 1649849553,4296752131,11190160825,29142853947,75897603297,197662332211
%N A297390 Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 neighboring 1.
%H A297390 R. H. Hardin, <a href="/A297390/b297390.txt">Table of n, a(n) for n = 1..210</a>
%F A297390 Empirical: a(n) = a(n-1) + 4*a(n-2) + 2*a(n-3) - 4*a(n-4).
%F A297390 Empirical g.f.: x*(1 + 2*x)*(3 - 2*x^2) / (1 - x - 4*x^2 - 2*x^3 + 4*x^4). - _Colin Barker_, Feb 28 2019
%e A297390 Some solutions for n=5:
%e A297390 ..0..1..0. .1..1..0. .0..1..1. .0..0..1. .0..1..1. .0..0..0. .1..0..0
%e A297390 ..0..0..1. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .1..0..0. .0..1..0
%e A297390 ..1..0..0. .0..1..1. .0..1..1. .0..0..0. .1..1..0. .0..1..0. .0..0..0
%e A297390 ..0..1..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
%e A297390 ..0..0..0. .1..1..0. .0..1..1. .1..0..0. .1..1..0. .1..1..0. .0..1..1
%Y A297390 Column 3 of A297395.
%K A297390 nonn
%O A297390 1,1
%A A297390 _R. H. Hardin_, Dec 29 2017