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%I #8 Feb 22 2019 15:27:05
%S 1,11,31,70,251,799,2266,7005,21780,65489,199273,610585,1857468,
%T 5653794,17249124,52563162,160123076,488054813,1487412562,4532419434,
%U 13812563405,42094180094,128277984857,390920465658,1191319783180,3630484158342
%N Number of n X 3 0..1 arrays with each 1 adjacent to 2 or 4 king-move neighboring 1s.
%H R. H. Hardin, <a href="/A296034/b296034.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + a(n-2) + 11*a(n-3) - 7*a(n-4) - 12*a(n-5) - 23*a(n-6) + 19*a(n-8) + 9*a(n-9) - 3*a(n-10) - 2*a(n-11).
%F Empirical g.f.: x*(1 + 9*x + 8*x^2 - 14*x^3 - 34*x^4 - 25*x^5 + 19*x^6 + 28*x^7 + 6*x^8 - 5*x^9 - 2*x^10) / (1 - 2*x - x^2 - 11*x^3 + 7*x^4 + 12*x^5 + 23*x^6 - 19*x^8 - 9*x^9 + 3*x^10 + 2*x^11). - _Colin Barker_, Feb 22 2019
%e Some solutions for n=5:
%e ..0..0..0. .0..0..0. .1..0..1. .0..1..0. .0..0..0. .1..0..1. .0..0..1
%e ..1..0..0. .1..0..0. .1..1..1. .1..1..0. .1..1..0. .1..1..1. .1..1..1
%e ..1..1..0. .1..1..1. .0..0..0. .0..0..0. .1..0..0. .0..0..0. .1..0..0
%e ..1..1..0. .0..0..1. .1..1..0. .1..1..0. .1..1..0. .0..0..0. .1..1..0
%e ..1..0..0. .0..1..1. .1..0..0. .0..1..0. .0..0..0. .0..0..0. .0..0..0
%Y Column 3 of A296039.
%K nonn
%O 1,2
%A _R. H. Hardin_, Dec 03 2017
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