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A183445 Number of n X 4 binary arrays with every 1 having exactly two king-move neighbors equal to 1.

%I A183445 #9 Mar 29 2018 06:28:59
%S A183445 1,13,30,72,283,831,2399,7761,23840,72396,225569,696929,2144537,
%T A183445 6635889,20510002,63318408,195704391,604826763,1868678179,5774848073,
%U A183445 17846507936,55148861000,170427655945,526681961257,1627610746225,5029867948101
%N A183445 Number of n X 4 binary arrays with every 1 having exactly two king-move neighbors equal to 1.
%C A183445 Column 4 of A183450.
%H A183445 R. H. Hardin, <a href="/A183445/b183445.txt">Table of n, a(n) for n = 1..200</a>
%F A183445 Empirical: a(n) = 3*a(n-1) + a(n-2) + 5*a(n-3) - 18*a(n-4) - 16*a(n-5) + 7*a(n-6) + 3*a(n-7) + a(n-8) - a(n-9).
%F A183445 Empirical g.f.: x*(1 + x)*(1 + 9*x - 19*x^2 - 17*x^3 + 7*x^4 + 3*x^5 + x^6 - x^7) / (1 - 3*x - x^2 - 5*x^3 + 18*x^4 + 16*x^5 - 7*x^6 - 3*x^7 - x^8 + x^9). - _Colin Barker_, Mar 29 2018
%e A183445 Some solutions for 5 X 4:
%e A183445 ..0..1..0..0....1..1..0..0....0..1..1..0....0..1..0..0....0..0..1..0
%e A183445 ..1..0..1..0....0..1..0..0....0..0..1..0....1..1..0..0....0..1..1..0
%e A183445 ..1..0..1..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A183445 ..0..1..0..0....1..1..0..0....0..1..0..0....0..1..0..0....1..0..0..0
%e A183445 ..0..0..0..0....0..1..0..0....1..1..0..0....0..1..1..0....1..1..0..0
%Y A183445 Cf. A183450.
%K A183445 nonn
%O A183445 1,2
%A A183445 _R. H. Hardin_, Jan 04 2011