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A268369
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Number of 3 X n arrays containing n copies of 0..3-1 with row sums equal.
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1
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0, 12, 216, 2700, 54000, 1054200, 20991600, 445365900, 9628264800, 212635396512, 4790810344320, 109495671909624, 2534856710978592, 59336480231336880, 1402136110916757216, 33409975384414912140, 801962422581013417152
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Conjecture: n^4*(1057*n^2 -3473*n +2902)*a(n) -(n-1) *(14798*n^5 -63420*n^4 +104199*n^3 -81821*n^2 +31698*n -4968)*a(n-1) +(-235711*n^6 +1717323*n^5 -5084885*n^4 +7773081*n^3 -6422772*n^2 +2716308*n -472176)*a(n-2) -96*(6*n -11) *(6*n-13) *(1057*n^2-1359*n+486) *(n-2)^2*a(n-3)=0. - R. J. Mathar, Feb 18 2016
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EXAMPLE
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Some solutions for n=5
..1..1..1..0..2....0..0..2..2..1....1..0..2..1..1....0..1..2..0..2
..0..1..0..2..2....1..1..1..2..0....1..0..2..0..2....0..1..1..1..2
..0..0..2..2..1....0..1..2..0..2....0..0..2..1..2....2..0..0..1..2
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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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