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%I #8 Feb 23 2019 09:56:42
%S 2,11,39,136,494,1785,6432,23201,83695,301885,1088905,3927736,
%T 14167501,51102728,184329596,664884245,2398264069,8650634510,
%U 31203185035,112551137627,405976459392,1464373342374,5282053272285,19052577620620
%N Number of n X 2 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1, 2 or 3 neighboring 1s.
%H R. H. Hardin, <a href="/A296593/b296593.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + a(n-2) + 4*a(n-3) + a(n-4) + a(n-6) - a(n-7) - a(n-8).
%F Empirical g.f.: x*(2 + 5*x + 4*x^2 + x^4 - 2*x^6 - x^7) / (1 - 3*x - x^2 - 4*x^3 - x^4 - x^6 + x^7 + x^8). - _Colin Barker_, Feb 23 2019
%e Some solutions for n=7:
%e ..0..0. .1..0. .0..1. .1..0. .0..1. .0..0. .0..0. .0..1. .1..0. .0..1
%e ..0..1. .1..0. .1..0. .1..0. .0..1. .0..1. .1..1. .0..1. .1..0. .1..0
%e ..1..0. .0..1. .1..0. .0..1. .0..1. .1..1. .0..1. .0..1. .1..0. .0..0
%e ..1..0. .0..1. .0..0. .0..1. .1..0. .0..1. .0..1. .1..0. .0..0. .0..0
%e ..0..1. .1..0. .1..1. .1..0. .1..0. .0..0. .0..1. .1..0. .0..0. .0..0
%e ..1..0. .1..1. .1..1. .0..1. .0..1. .0..1. .1..1. .1..0. .0..1. .0..1
%e ..1..1. .1..0. .0..0. .1..1. .1..0. .1..1. .0..1. .1..0. .1..1. .0..1
%Y Column 2 of A296599.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 16 2017
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