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%I #8 May 03 2021 12:57:25
%S 1,7,45,161,899,4023,19387,92169,436539,2077281,9861263,46848707,
%T 222547181,1057107041,5021579939,23853406065,113308835575,
%U 538241104209,2556757711375,12145141483565,57691981461499,274049091332625
%N Number of n X 4 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,4,1,0,1 for x=0,1,2,3,4.
%C Every 0 is next to 0 2's, every 1 is next to 1 4's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 1's.
%C Column 4 of A197373.
%H R. H. Hardin, <a href="/A197369/b197369.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) +10*a(n-2) +18*a(n-3) -7*a(n-4) -33*a(n-5) -58*a(n-6) +13*a(n-7) +22*a(n-8) -31*a(n-9) +18*a(n-10) -3*a(n-11).
%e Some solutions containing all values 0 to 4 for n=5
%e ..0..0..1..2....0..0..0..0....0..0..1..2....2..1..0..0....0..0..1..2
%e ..0..1..4..1....0..0..0..0....0..1..4..1....1..4..1..0....0..1..4..1
%e ..3..0..1..0....0..1..0..3....3..0..1..0....0..1..0..0....3..0..1..0
%e ..0..0..3..0....1..4..1..0....0..0..3..0....3..0..0..3....0..0..0..3
%e ..0..3..0..0....2..1..0..0....0..0..0..0....0..0..3..0....0..0..0..0
%Y Cf. A197373.
%K nonn
%O 1,2
%A _R. H. Hardin_ Oct 14 2011
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