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%I #8 May 08 2018 08:37:53
%S 0,1,2,0,6,2,8,12,10,32,26,58,82,104,204,238,424,606,870,1438,1952,
%T 3156,4602,6848,10634,15354,23794,35192,52844,80254,118744,180686,
%U 269382,405118,610576,911988,1377066,2061328,3099290,4659546,6984594,10512968
%N Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,3,2,1,4 for x=0,1,2,3,4.
%C Every 0 is next to 0 0's, every 1 is next to 1 3's, every 2 is next to 2 2's, every 3 is next to 3 1's, every 4 is next to 4 4's.
%C Column 2 of A196078.
%H R. H. Hardin, <a href="/A196072/b196072.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = a(n-2) +a(n-3) +2*a(n-5).
%F Empirical g.f.: x^2*(1 + 2*x - x^2 + 3*x^3) / (1 - x^2 - x^3 - 2*x^5). - _Colin Barker_, May 08 2018
%e All solutions for n=5:
%e ..2..2....2..2....1..0....1..0....0..1....0..1
%e ..2..2....2..2....3..1....3..1....1..3....1..3
%e ..0..1....1..0....1..1....1..0....0..1....1..1
%e ..1..3....3..1....1..3....2..2....2..2....3..1
%e ..0..1....1..0....0..1....2..2....2..2....1..0
%Y Cf. A196078.
%K nonn
%O 1,3
%A _R. H. Hardin_, Sep 27 2011
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