OFFSET
1,4
COMMENTS
a(n) = sum of divisors d of n from set A001694(m) - powerful numbers for m >=2.
LINKS
FORMULA
EXAMPLE
For n = 12, set of such divisors is {4}; a(12) = 4.
MATHEMATICA
f[p_, e_] := (p^(e+1)-1)/(p-1) - p; a[1] = 0; a[n_] := Times @@ f @@@ FactorInteger[n] - 1; Array[a, 100] (* Amiram Eldar, Aug 29 2023 *)
PROG
(PARI) A183099(n) = (sumdiv(n, d, ispowerful(d)*d) - 1); \\ Antti Karttunen, Oct 07 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaroslav Krizek, Dec 25 2010
STATUS
approved