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A211766
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Number of -3..3 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 two, three, four, five, six, seven or eight distinct values for every i,j,k<=n.
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1
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48, 330, 2264, 15512, 106128, 725040, 4946132, 33693740, 229205328, 1557067320, 10563664724, 71575622300, 484371525216, 3273973248600, 22104207166532, 149072726510492, 1004302970917488, 6759180631475928, 45446982868078004
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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) = 24*a(n-1) - 206*a(n-2) + 684*a(n-3) - 251*a(n-4) - 1740*a(n-5) - 1210*a(n-6) - 300*a(n-7) - 24*a(n-8).
Empirical g.f.: 2*x*(24 - 411*x + 2116*x^2 - 1838*x^3 - 6724*x^4 - 4393*x^5 - 1062*x^6 - 84*x^7) / ((1 - 6*x - x^2)*(1 - 6*x - 2*x^2)*(1 - 6*x - 3*x^2)*(1 - 6*x - 4*x^2)). - Colin Barker, Jul 20 2018
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EXAMPLE
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Some solutions for n=5:
..1...-1....3....1...-1...-1...-1....2...-3...-2...-3....2...-1....2....3....0
..1....3...-1....0....1...-1...-3....0...-2....1....3....3...-3...-3...-3...-3
.-1...-3...-1...-3....0....1....1....3....2...-1...-2...-3....1...-3....0....0
..1...-1...-2....1...-3....2....1...-3...-3...-1...-2...-3....2....0....2....1
.-3...-1...-2...-2....2....3...-2....0....1....1...-1....3...-2....2....3....0
..1...-2....1....2....3....2....3....1....1...-1...-2...-1...-2...-3....0...-1
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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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