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%I #8 Apr 10 2018 04:52:10
%S 49,61,82,124,202,358,658,1258,2434,4786,9442,18754,37282,74338,
%T 148258,296098,591394,1181986,2362402,4723234,9443362,18883618,
%U 37761058,75515938,151019554,302026786,604028962,1208033314,2416017442,4831985698
%N 1/16 the number of (n+1) X 4 0..3 arrays with all 2 X 2 subblocks having the same four values.
%C Column 3 of A184039.
%H R. H. Hardin, <a href="/A184033/b184033.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).
%F Conjectures from _Colin Barker_, Apr 10 2018: (Start)
%F G.f.: x*(49 - 86*x - 101*x^2 + 172*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).
%F a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 34 for n even.
%F a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 34 for n odd.
%F (End)
%e Some solutions for 3 X 4:
%e ..0..0..1..2....0..1..0..1....0..2..3..2....2..2..2..2....1..3..1..3
%e ..1..2..0..0....3..2..3..2....3..0..0..0....0..0..0..0....3..2..3..2
%e ..0..0..1..2....1..0..1..0....0..2..3..2....2..2..2..2....1..3..1..3
%Y Cf. A184039.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 08 2011
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