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%I #4 Apr 12 2012 06:14:57
%S 21,89,353,1373,5225,19645,73105,270125,992545,3631741,13245457,
%T 48187085,174966209,634348221,2297224145,8311862669,30054358337,
%U 108618731197,392419038993,1417394738125,5118764739265,18484320138301,66746754619345
%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, three or four distinct values for every i<=n and j<=n
%H R. H. Hardin, <a href="/A211464/b211464.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 10*a(n-1) -16*a(n-2) -118*a(n-3) +321*a(n-4) +560*a(n-5) -1724*a(n-6) -1636*a(n-7) +3492*a(n-8) +2984*a(n-9) -1216*a(n-10) -608*a(n-11) +192*a(n-12)
%e Some solutions for n=5
%e ..0....2...-2...-1....1...-1....0....2....2....0....0...-1....2....0....0....0
%e .-2...-1....1....1....0...-2...-2....0....1....0....1....0....0....2...-1....0
%e ..2...-2....2...-2...-2....2....0....2...-2....0....0...-1....0....0....2....2
%e ..1....1...-1....2...-1...-2...-1....0....2...-2....0....1....0....2....0....0
%e ..2....0....2...-1....0...-1...-2....0....1...-1....0....2....0....0....2....1
%e ..1....0...-1....2...-1...-2....0...-1...-2....0...-1...-2....1...-1...-1...-2
%K nonn
%O 1,1
%A _R. H. Hardin_ Apr 12 2012
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