cp's OEIS Frontend

A184035 1/16 the number of (n+1) X 6 0..3 arrays with all 2 X 2 subblocks having the same four values.

%I A184035 #8 Apr 10 2018 05:56:47
%S A184035 169,181,202,244,322,478,778,1378,2554,4906,9562,18874,37402,74458,
%T A184035 148378,296218,591514,1182106,2362522,4723354,9443482,18883738,
%U A184035 37761178,75516058,151019674,302026906,604029082,1208033434,2416017562,4831985818
%N A184035 1/16 the number of (n+1) X 6 0..3 arrays with all 2 X 2 subblocks having the same four values.
%C A184035 Column 5 of A184039.
%H A184035 R. H. Hardin, <a href="/A184035/b184035.txt">Table of n, a(n) for n = 1..200</a>
%F A184035 Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
%F A184035 Conjectures from _Colin Barker_, Apr 10 2018: (Start)
%F A184035 G.f.: x*(169 - 326*x - 341*x^2 + 652*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
%F A184035 a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 154 for n even.
%F A184035 a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 154 for n odd.
%F A184035 (End)
%e A184035 Some solutions for 3 X 6:
%e A184035 ..1..2..0..3..0..2....0..0..3..1..3..1....3..2..2..2..3..2....0..0..2..0..0..3
%e A184035 ..0..3..1..2..1..3....3..1..0..0..0..0....2..2..3..2..2..2....2..3..0..3..2..0
%e A184035 ..1..2..0..3..0..2....0..0..3..1..3..1....3..2..2..2..3..2....0..0..2..0..0..3
%Y A184035 Cf. A184039.
%K A184035 nonn
%O A184035 1,1
%A A184035 _R. H. Hardin_, Jan 08 2011