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A105570
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Nonsquarefree numbers in place: a(n) = n if n is not squarefree, 0 otherwise.
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1
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0, 0, 0, 0, 4, 0, 0, 0, 8, 9, 0, 0, 12, 0, 0, 0, 16, 0, 18, 0, 20, 0, 0, 0, 24, 25, 0, 27, 28, 0, 0, 0, 32, 0, 0, 0, 36, 0, 0, 0, 40, 0, 0, 0, 44, 45, 0, 0, 48, 49, 50, 0, 52, 0, 54, 0, 56, 0, 0, 0, 60, 0, 0, 63, 64, 0, 0, 0, 68, 0, 0, 0, 72, 0, 0, 75, 76, 0, 0, 0, 80, 81, 0, 0, 84, 0, 0, 0, 88, 0
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OFFSET
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0,5
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LINKS
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FORMULA
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a(n) = n - abs(mu(n))*n.
Sum_{k=1..n} a(k) ~ c * n^2, where c = (1 - 1/zeta(2))/2 = 0.1960364490... . - Amiram Eldar, Feb 22 2024
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MATHEMATICA
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Table[If[SquareFreeQ[n], 0, n], {n, 0, 100}] (* Harvey P. Dale, Aug 13 2016 *)
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PROG
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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