|
%I #5 Mar 24 2018 16:03:40
%S 0,1,1,2,3,7,14,31,67,148,325,717,1580,3485,7685,16950,37383,82451,
%T 181850,401083,884615,1951080,4303241,9491097,20933272,46169785,
%U 101830665,224594602,495358987,1092548639,2409691878,5314742743
%N Half the number of nX3 binary arrays with each element equal to at least two neighbors
%C Column 3 of A180760
%H R. H. Hardin, <a href="/A180752/b180752.txt">Table of n, a(n) for n=1..99</a>
%F Empirical: a(n) = 2*a(n-1) + a(n-2) - a(n-3) - a(n-5).
%F Empirical: G.f.: -x^2*(-1+x+x^3+x^2) / ( (x-1)*(1+x)*(x^3+2*x-1) ). a(n)-a(n-2) = A052980(n-3). - _R. J. Mathar_, Mar 24 2018
%K nonn
%O 1,4
%A _R. H. Hardin_ Sep 20 2010
|
