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%I #9 May 14 2018 05:50:24
%S 0,0,8,0,8,32,16,64,152,160,424,832,1216,2688,4968,8384,16936,30944,
%T 55440,107072,196152,359776,679880,1251456,2315136,4330752,8000840,
%U 14842752,27638984,51176864,95010832,176575552,327357272,607795744
%N Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,3,1,1,1 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 1's, every 3 is next to 3 1's, every 4 is next to 4 1's.
%C Column 2 of A197623.
%H R. H. Hardin, <a href="/A197617/b197617.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = a(n-2) +4*a(n-3) +a(n-4).
%F Empirical g.f.: 8*x^3 / (1 - x^2 - 4*x^3 - x^4). - _Colin Barker_, May 14 2018
%e All solutions for n=5:
%e ..0..1....1..0....1..2....1..0....1..2....2..1....2..1....0..1
%e ..1..3....3..1....3..1....3..1....3..1....1..3....1..3....1..3
%e ..1..1....1..1....1..1....1..1....1..1....1..1....1..1....1..1
%e ..3..1....1..3....1..3....1..3....1..3....3..1....3..1....3..1
%e ..1..0....0..1....0..1....2..1....2..1....1..0....1..2....1..2
%Y Cf. A197623.
%K nonn
%O 1,3
%A _R. H. Hardin_, Oct 16 2011
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