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Nonsquarefree unitary abundant numbers.
3

%I #12 Oct 05 2019 04:25:16

%S 150,294,420,630,660,726,750,780,840,924,990,1014,1020,1050,1092,1140,

%T 1170,1380,1386,1428,1470,1530,1596,1638,1650,1710,1734,1740,1860,

%U 1890,1950,2058,2070,2142,2166,2220,2394,2460,2550,2580,2610,2790,2820,2850,2940

%N Nonsquarefree unitary abundant numbers.

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

%C The odd terms of this sequence are A129486.

%H Amiram Eldar, <a href="/A292705/b292705.txt">Table of n, a(n) for n = 1..10000</a>

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

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

%Y Cf. A013929, A034683, A129486.

%K nonn

%O 1,1

%A _Amiram Eldar_, Sep 21 2017