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A088818 Abundance-radius of n = Abs[sigma[n]-2n]<=log[log[n]]. 1
6, 16, 28, 32, 64, 128, 256, 496, 512, 1024, 1952, 2048, 4096, 8128, 8192, 16384, 32768, 32896, 65536, 130304, 131072, 262144, 522752, 524288, 1048576, 2097152, 4194304, 8382464, 8388608, 16777216, 33550336, 33554432, 67108864, 134193152 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

Perfect numbers are here.

It is an infinite sequence since includes A000079,

[as quasiperfect numbers].

MATHEMATICA

abu[x_] := Abs[DivisorSigma[1, x]-2*x] Do[If[ !Greater[abu[n], Log[Log[n]]//N], Print[n]], {n, 1, 1000000}

CROSSREFS

Cf. A088009-A088012, A077374, A000396, A000079.

Sequence in context: A320693 A274848 A201020 * A032422 A164052 A264938

Adjacent sequences:  A088815 A088816 A088817 * A088819 A088820 A088821

KEYWORD

nonn

AUTHOR

Labos Elemer, Oct 20 2003

EXTENSIONS

a(28)-a(34) from Donovan Johnson, Dec 21 2008

STATUS

approved

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Last modified August 21 06:02 EDT 2019. Contains 326162 sequences. (Running on oeis4.)