%I #6 Mar 26 2018 14:25:17

%S 8,57,417,3032,22077,160697,1169792,8515337,61986457,451223152,

%T 3284626797,23910060017,174050512312,1266980540057,9222838063377,

%U 67136581219272,488712965249117,3557529413370537,25896623226618032

%N Number of n X 3 binary matrices with no 2 X 2 block having four 1's.

%C Column 3 of A181253.

%H R. H. Hardin, <a href="/A181246/b181246.txt">Table of n, a(n) for n=1..200</a>

%F Empirical: a(n) = 6*a(n-1) + 10*a(n-2) - 5*a(n-3).

%F Empirical g.f.: x*(8 + 9*x - 5*x^2) / (1 - 6*x - 10*x^2 + 5*x^3). - _Colin Barker_, Mar 26 2018

%Y Cf. A181253.

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 10 2010