cp's OEIS Frontend

A183315 Number of n X 3 binary arrays with an element zero only if there are an even number of ones to its left and an even number of ones above it.

%I A183315 #8 Mar 27 2018 08:49:31
%S A183315 5,13,43,124,377,1109,3305,9767,28959,85677,253693,750777,2222308,
%T A183315 6577131,19466625,57614249,170519517,504678557,1493676557,4420766649,
%U A183315 13083945331,38723960052,114609540289,339204648201,1003928499625
%N A183315 Number of n X 3 binary arrays with an element zero only if there are an even number of ones to its left and an even number of ones above it.
%C A183315 Column 3 of A183322.
%H A183315 R. H. Hardin, <a href="/A183315/b183315.txt">Table of n, a(n) for n = 1..200</a>
%F A183315 Empirical: a(n) = a(n-1) + 9*a(n-2) - 3*a(n-3) - 21*a(n-4) + a(n-5) + 13*a(n-6) + a(n-7) - a(n-8).
%F A183315 Empirical g.f.: x*(5 + 8*x - 15*x^2 - 21*x^3 + 10*x^4 + 13*x^5 - x^7) / (1 - x - 9*x^2 + 3*x^3 + 21*x^4 - x^5 - 13*x^6 - x^7 + x^8). - _Colin Barker_, Mar 27 2018
%e A183315 Some solutions for 5 X 3:
%e A183315 ..1..1..1....0..1..1....1..1..0....1..1..0....1..1..0....1..1..1....1..1..0
%e A183315 ..1..1..1....1..1..1....1..1..0....1..1..0....1..1..1....1..1..1....1..1..1
%e A183315 ..0..0..0....1..1..1....0..0..0....0..1..1....1..1..1....0..0..0....0..0..1
%e A183315 ..0..1..1....0..1..1....0..0..0....0..1..1....1..1..0....1..1..0....0..0..1
%e A183315 ..0..1..1....0..0..1....0..1..1....0..0..1....1..1..0....1..1..1....0..1..1
%Y A183315 Cf. A183322.
%K A183315 nonn
%O A183315 1,1
%A A183315 _R. H. Hardin_, Jan 03 2011