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A292705 Nonsquarefree unitary abundant numbers. 3
150, 294, 420, 630, 660, 726, 750, 780, 840, 924, 990, 1014, 1020, 1050, 1092, 1140, 1170, 1380, 1386, 1428, 1470, 1530, 1596, 1638, 1650, 1710, 1734, 1740, 1860, 1890, 1950, 2058, 2070, 2142, 2166, 2220, 2394, 2460, 2550, 2580, 2610, 2790, 2820, 2850, 2940 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Most unitary abundant numbers are squarefree. For example, there are 70030 unitary abundant numbers below 10^6, and only 14685 are nonsquarefree.

The odd terms of this sequence are A129486.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

usigma[n_]:=If[n==1, 1, Times @@ (1 + Power @@@ FactorInteger[n])];

aQ[n_]:=!SquareFreeQ[n] && usigma[n] > 2 n; Select[Range[10^4], aQ]

CROSSREFS

Cf. A013929, A034683, A129486.

Sequence in context: A008889 A184075 A207044 * A335145 A063829 A291959

Adjacent sequences:  A292702 A292703 A292704 * A292706 A292707 A292708

KEYWORD

nonn

AUTHOR

Amiram Eldar, Sep 21 2017

STATUS

approved

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Last modified August 9 04:41 EDT 2022. Contains 356016 sequences. (Running on oeis4.)