OFFSET
1,1
COMMENTS
The numbers of terms not exceeding 10^k, for k = 2, 3, ..., are 7, 79, 843, 8230, 83005, 826875, 8275895, 82790525, 827718858, 8276571394, ... . Apparently, the asymptotic density of this sequence exists and equals 0.0827... .
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
30 is a term since its aliquot squarefree divisors are {1, 2, 3, 5, 6, 10, 15} and their sum is 42 > 30.
60 is a term since its aliquot squarefree divisors are {1, 2, 3, 5, 6, 10, 15, 30} and their sum is 72 > 60.
MATHEMATICA
s[n_] := Times @@ (1 + (f = FactorInteger[n])[[;; , 1]]) - If[AllTrue[f[[;; , 2]], # == 1 &], n, 0]; Select[Range[2, 1000], s[#] > # &]
PROG
(PARI) is(n) = {my(f = factor(n), s); s = prod(i=1, #f~, f[i, 1]+1); if(n==1 || vecmax(f[, 2]) == 1, s -= n); s > n};
CROSSREFS
Subsequence of A005101.
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 09 2022
STATUS
approved