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%I #4 Apr 12 2012 06:13:21
%S 25,65,169,407,977,2283,5313,12259,28253,65023,149817,345739,799821,
%T 1855467,4317293,10077003,23592677,55403427,130474345,308095007,
%U 729314485,1730363331,4113892073,9798957667,23379161753,55863031875
%N Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having one, two or three distinct values for every i<=n and j<=n
%H R. H. Hardin, <a href="/A211462/b211462.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) -a(n-2) -55*a(n-3) +70*a(n-4) +193*a(n-5) -357*a(n-6) -320*a(n-7) +802*a(n-8) +238*a(n-9) -922*a(n-10) -39*a(n-11) +533*a(n-12) -29*a(n-13) -136*a(n-14) +6*a(n-15) +12*a(n-16)
%e Some solutions for n=5
%e .-1....1....0....2...-2....0...-2....1....0....0...-2...-1....0....0...-1...-2
%e ..0...-1...-2...-2...-1....1....2....0....2....0....0....0....0...-1....1....2
%e .-1...-1....0....0....0....0...-2....0...-2...-2...-2....0...-2....0....1...-2
%e ..0...-1...-2...-2...-1....1....2...-2....2....2....0...-1....0....0....1....0
%e ..1...-1....2....2....0...-1...-2....0....0...-2...-2....0....0....0...-1....0
%e ..2...-1....2....2...-1...-1...-2...-2....0....0....2....0....1....0...-1...-2
%K nonn
%O 1,1
%A _R. H. Hardin_ Apr 12 2012
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