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A233078 Number of n X 4 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.

%I A233078 #8 Oct 07 2018 08:36:12
%S A233078 14,662,32414,1588262,77824814,3813415862,186857377214,9156011483462,
%T A233078 448644562689614,21983583571791062,1077195595017762014,
%U A233078 52782584155870338662,2586346623637646594414,126730984558244683126262
%N A233078 Number of n X 4 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.
%H A233078 R. H. Hardin, <a href="/A233078/b233078.txt">Table of n, a(n) for n = 1..210</a>
%F A233078 Empirical: a(n) = 50*a(n-1) - 49*a(n-2).
%F A233078 Conjectures from _Colin Barker_, Oct 07 2018: (Start)
%F A233078 G.f.: 2*x*(7 - 19*x) / ((1 - x)*(1 - 49*x)).
%F A233078 a(n) = (49 + 27*49^n) / 98.
%F A233078 (End)
%e A233078 Some solutions for n=3:
%e A233078 ..0..0..1..3....0..1..1..3....0..0..0..0....0..0..1..1....0..1..1..0
%e A233078 ..2..3..1..1....3..1..1..3....0..1..0..0....1..3..3..1....3..1..1..0
%e A233078 ..1..0..1..3....1..3..1..1....0..1..1..3....1..3..3..1....3..1..0..2
%Y A233078 Column 4 of A233082.
%K A233078 nonn
%O A233078 1,1
%A A233078 _R. H. Hardin_, Dec 03 2013