%I #9 Mar 28 2018 08:14:23
%S 2,3,5,12,21,41,84,171,355,732,1517,3165,6608,13809,28871,60398,
%T 126425,264681,554188,1160473,2430233,5089614,10659415,22324873,
%U 46757436,97930229,205109405,429591772,899761459,1884515059,3947047760,8266953369
%N Number of n X 2 binary arrays with no element equal to the sum mod 3 of its horizontal and vertical neighbors.
%C Column 2 of A183368.
%H R. H. Hardin, <a href="/A183364/b183364.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 2*a(n-1) + a(n-3) - 4*a(n-6) - 3*a(n-7) + a(n-10).
%F Empirical g.f.: x*(1 + x)*(2 - 3*x + 2*x^2 - 2*x^3 - 4*x^4 - 2*x^5 + x^8) / (1 - 2*x - x^3 + 4*x^6 + 3*x^7 - x^10). - _Colin Barker_, Mar 28 2018
%e Some solutions for 5 X 2:
%e ..0..0....1..0....0..1....0..1....0..0....1..1....1..1....0..1....1..0....1..1
%e ..1..1....0..0....0..0....1..0....1..1....1..1....1..1....1..0....0..0....1..1
%e ..1..1....1..1....1..1....0..0....1..1....1..1....0..0....0..0....0..1....1..1
%e ..0..0....1..1....1..1....0..1....1..1....1..1....1..0....1..1....0..0....0..0
%e ..1..0....1..1....1..1....1..0....1..1....0..0....0..1....1..1....1..0....1..0
%Y Cf. A183368.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 04 2011
|