OFFSET
1,6
MATHEMATICA
f[p_, e_] := (p^(e+1)-2*p+1)/(p-1); r[1] = 1; r[n_] := (Times @@ f @@@ FactorInteger[n])/n; Select[r /@ Range[10^5], IntegerQ] (* Amiram Eldar, Jul 07 2022 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(1)=1 prepended and offset corrected by Michel Marcus, Jun 02 2016
a(10) and a(11) switched and missing term a(13) inserted by Amiram Eldar, Jul 07 2022
STATUS
approved