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%I #4 Apr 16 2012 07:09:40
%S 16,48,128,322,780,1874,4400,10458,24332,57922,134744,322650,753100,
%T 1815874,4256984,10332338,24326116,59383402,140337800,344230370,
%U 816065860,2009539410,4776207920,11798294714,28099290420,69585826082
%N Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having four, five, six, seven or eight distinct values for every i,j,k<=n
%H R. H. Hardin, <a href="/A211598/b211598.txt">Table of n, a(n) for n = 1..55</a>
%F Empirical: a(n) = 2*a(n-1) +16*a(n-2) -31*a(n-3) -97*a(n-4) +178*a(n-5) +284*a(n-6) -473*a(n-7) -418*a(n-8) +578*a(n-9) +288*a(n-10) -270*a(n-11) -72*a(n-12) +36*a(n-13)
%e Some solutions for n=5
%e ..1....2...-1....0....1...-2....1....2....0....0....0...-1...-1....1...-2....1
%e ..0....0....0...-1...-2...-1....2....1...-1...-2....1....0....0....0...-1....0
%e .-1....2...-1...-2...-1....0...-1....0....2...-1....0....1...-1....2....0....2
%e ..0...-1....0....0...-2...-1...-2....1....1...-2...-1....2...-2....1...-1....1
%e ..1....2...-1...-1...-1....0...-1....2....2....1...-2....1....1....2...-2....2
%e ..0...-1....0....0....0....1...-2....1....1...-2...-1....2....2...-1...-1....0
%K nonn
%O 1,1
%A _R. H. Hardin_ Apr 16 2012
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