OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
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
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 05 2003
STATUS
approved