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%I #8 Feb 28 2019 18:52:08
%S 1,4,22,42,105,349,1057,2834,8216,24556,71651,207409,608985,1791636,
%T 5251548,15401954,45271039,133066199,390990659,1149260888,3379206474,
%U 9935995300,29215600841,85913309363,252656693545,743030170284
%N Number of 4 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 neighboring 1s.
%H R. H. Hardin, <a href="/A297434/b297434.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + a(n-2) + a(n-4) - 33*a(n-5) - 7*a(n-6) + 21*a(n-7) + 3*a(n-8) + 2*a(n-9) + 3*a(n-10) + 5*a(n-11) - 2*a(n-12).
%F Empirical g.f.: x*(1 + x + 9*x^2 - 28*x^3 - 44*x^4 + 21*x^5 + 22*x^6 + 5*x^7 + 5*x^8 + 8*x^9 + 3*x^10 - 2*x^11) / ((1 + x)*(1 - 4*x + 3*x^2 - 3*x^3 + 2*x^4 + 31*x^5 - 24*x^6 + 3*x^7 - 6*x^8 + 4*x^9 - 7*x^10 + 2*x^11)). - _Colin Barker_, Feb 28 2019
%e Some solutions for n=5:
%e ..0..0..0..0..0. .0..0..0..0..0. .0..1..1..0..0. .0..0..0..0..0
%e ..0..0..0..0..0. .0..1..1..1..0. .0..1..1..0..0. .0..0..0..0..0
%e ..1..1..1..0..0. .0..0..1..0..0. .0..0..0..0..0. .1..1..0..0..0
%e ..0..1..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..1..1..0..0
%Y Row 4 of A297431.
%K nonn
%O 1,2
%A _R. H. Hardin_, Dec 30 2017
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