cp's OEIS Frontend

A184755 Half the number of n X 3 binary arrays with no 1 having an adjacent 1 both above and to its left.

%I A184755 #9 Apr 14 2018 13:11:22
%S A184755 4,25,163,1056,6847,44391,287802,1865917,12097367,78431296,508496451,
%T A184755 3296753387,21373960178,138574567177,898425491035,5824794400480,
%U A184755 37764099690423,244837350020575,1587362824918602,10291406673539877
%N A184755 Half the number of n X 3 binary arrays with no 1 having an adjacent 1 both above and to its left.
%C A184755 Column 3 of A184761.
%H A184755 R. H. Hardin, <a href="/A184755/b184755.txt">Table of n, a(n) for n = 1..200</a>
%F A184755 Empirical: a(n) = 5*a(n-1) + 9*a(n-2) + 4*a(n-3).
%F A184755 Empirical g.f.: x*(4 + 5*x + 2*x^2) / (1 - 5*x - 9*x^2 - 4*x^3). - _Colin Barker_, Apr 14 2018
%e A184755 Some solutions for 5 X 3:
%e A184755 ..0..1..0....1..0..1....1..1..0....1..0..0....0..0..0....0..1..1....1..1..0
%e A184755 ..0..1..0....1..0..1....1..0..0....0..1..0....1..1..1....1..0..0....1..0..1
%e A184755 ..0..1..0....1..0..1....0..1..0....0..0..1....1..0..0....0..1..1....0..1..0
%e A184755 ..0..1..0....1..0..1....0..1..0....0..0..0....1..0..0....1..0..0....0..0..0
%e A184755 ..0..0..0....1..0..0....1..0..0....0..1..0....1..1..1....1..0..1....1..1..0
%Y A184755 Cf. A184761.
%K A184755 nonn
%O A184755 1,1
%A A184755 _R. H. Hardin_, Jan 21 2011