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A144672
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Numbers x,y,z such that UnitarySigma(x) = UnitarySigma(y) = UnitarySigma(z) = 3*(x*y*z)^(1/2)/(- x^(1/2) + 8*y^(1/2) - 5*z^(1/2)), z<=y<=x; sequence gives x.
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4
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2, 20, 24, 360, 816, 1056, 12240, 15840, 29120, 181632, 337977, 2724480, 93358848, 1400382720
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OFFSET
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1,1
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COMMENTS
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a(11) is the smallest term for x!=y, y!=z, x!=z.
If x=y=z then we get multiply unitary perfect numbers such that UnitarySigma(x)=3x/2.
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LINKS
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EXAMPLE
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Factorization of a(11) : 17*3^2*47^2.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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