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A211598
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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
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1
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16, 48, 128, 322, 780, 1874, 4400, 10458, 24332, 57922, 134744, 322650, 753100, 1815874, 4256984, 10332338, 24326116, 59383402, 140337800, 344230370, 816065860, 2009539410, 4776207920, 11798294714, 28099290420, 69585826082
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OFFSET
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1,1
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LINKS
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FORMULA
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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)
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EXAMPLE
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Some solutions for n=5
..1....2...-1....0....1...-2....1....2....0....0....0...-1...-1....1...-2....1
..0....0....0...-1...-2...-1....2....1...-1...-2....1....0....0....0...-1....0
.-1....2...-1...-2...-1....0...-1....0....2...-1....0....1...-1....2....0....2
..0...-1....0....0...-2...-1...-2....1....1...-2...-1....2...-2....1...-1....1
..1....2...-1...-1...-1....0...-1....2....2....1...-2....1....1....2...-2....2
..0...-1....0....0....0....1...-2....1....1...-2...-1....2....2...-1...-1....0
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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