A292705 Nonsquarefree unitary abundant numbers.

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

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