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A088008
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Solutions to sigma(x) - 2x <= x^(1/3), both even and odd. Abundance-radius = abs(sigma(n)-2n) does not exceed 3rd root of n.
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5
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1, 2, 4, 6, 8, 10, 16, 20, 28, 32, 64, 70, 88, 104, 110, 128, 136, 152, 256, 315, 464, 496, 512, 592, 650, 836, 884, 1012, 1024, 1155, 1696, 1758, 1842, 1866, 1878, 1888, 1902, 1952, 1986, 2022, 2048, 2082, 2094, 2118, 2144, 2154, 2202, 2238, 2272, 2274, 2298
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OFFSET
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1,2
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LINKS
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Amiram Eldar, Table of n, a(n) for n = 1..10000
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MATHEMATICA
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abu[x_] := Abs[DivisorSigma[1, x]-2*x] Do[If[ !Greater[abu[n], n^(1/3)//N], Print[n]], {n, 1, 100000}]
Select[Range[2300], Abs[DivisorSigma[1, #]-2#]<=CubeRoot[#]&] (* Harvey P. Dale, Feb 22 2023 *)
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CROSSREFS
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Cf. A077374, A088007-A088012, A000396, A000079, A005100, A005101.
Sequence in context: A302299 A227992 A175299 * A067720 A078106 A353764
Adjacent sequences: A088005 A088006 A088007 * A088009 A088010 A088011
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KEYWORD
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nonn
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AUTHOR
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Labos Elemer, Oct 20 2003
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STATUS
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approved
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