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%I #8 Jul 19 2018 09:50:20
%S 16,28,44,74,116,194,308,518,836,1418,2324,3974,6596,11354,19028,
%T 32918,55556,96458,163604,284774,484676,845114,1441748,2516918,
%U 4300676,7513898,12852884,22467974,38460356,67256474,115184468,201474518,345160196
%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 three, four or five distinct values for every i,j,k<=n.
%H R. H. Hardin, <a href="/A211570/b211570.txt">Table of n, a(n) for n = 1..64</a>
%F Empirical: a(n) = a(n-1) + 5*a(n-2) - 5*a(n-3) - 6*a(n-4) + 6*a(n-5).
%F Empirical g.f.: 2*x*(8 + 6*x - 32*x^2 - 15*x^3 + 29*x^4) / ((1 - x)*(1 - 2*x^2)*(1 - 3*x^2)). - _Colin Barker_, Jul 19 2018
%e Some solutions for n=5:
%e .-2....0....0....1....0....2....1....0....1...-1...-1....0....1....0....1...-1
%e .-1....2...-2....0...-1....1....0....1....0....0...-2...-1....0....2....2....0
%e ..0....0....0....1...-2....0....1....0....1....1...-1....0...-1....0....1...-1
%e ..1...-2...-2....2...-1...-1....2....1....0....0....0....1....0....2....0....0
%e ..2....0....0....1...-2...-2....1....0...-1...-1....1....2...-1....0...-1....1
%e ..1...-2...-2....0...-1...-1....2...-2...-2...-2....2....1...-2...-1....0....0
%K nonn
%O 1,1
%A _R. H. Hardin_, Apr 16 2012
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