OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1600
MATHEMATICA
Select[Range[10^6], IntegerQ@ DivisorSigma[-1, #] &] (* or, using the b-file at A007691: *)
Map[PrimeOmega, DeleteCases[Import["https://oeis.org/A007691/b007691.txt", "Data"], _?(Length@ # == 0 &)][[1 ;; 82, -1]] ] (* Michael De Vlieger, Mar 19 2021 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Mar 19 2021
STATUS
approved