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A087245
Nonsquarefree abundant numbers.
4
12, 18, 20, 24, 36, 40, 48, 54, 56, 60, 72, 80, 84, 88, 90, 96, 100, 104, 108, 112, 120, 126, 132, 140, 144, 150, 156, 160, 162, 168, 176, 180, 192, 196, 198, 200, 204, 208, 216, 220, 224, 228, 234, 240, 252, 260, 264, 270, 272, 276, 280, 288, 294, 300, 304
OFFSET
1,1
LINKS
EXAMPLE
m = 20 = 2*2*5 and sigma(20) = 42 > 2m = 40.
MATHEMATICA
aQ[n_] := !SquareFreeQ[n] && DivisorSigma[1, n] > 2n; Select[Range[300], aQ] (* Amiram Eldar, Sep 21 2019 *)
PROG
(PARI) isok(n) = !issquarefree(n) && (sigma(n) > 2*n); \\ Michel Marcus, Sep 21 2019
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 05 2003
STATUS
approved