OFFSET
1,1
COMMENTS
2^n is a term for all n>=1. - Amiram Eldar, Aug 26 2022
EXAMPLE
Factorizations: even examples: 2, 2^2, 2^3, 2^4,...; odd examples: a(6) = 3^2*7, a(17) = 3^4*7*61, a(30) = 3^6*7*61*547.
MATHEMATICA
f[p_, e_] := 1 + (p^(e + 1) - 1)/(p - 1); s[n_] := Times @@ f @@@ FactorInteger[n]; s[1] = 1; Select[Range[5*10^6], s[#] == 2*# &] (* Amiram Eldar, Aug 26 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Yasutoshi Kohmoto Mar 13 2000
EXTENSIONS
Corrected by Franklin T. Adams-Watters, Oct 25 2006
a(30) corrected and a(31)-a(35) added by Amiram Eldar, Aug 26 2022
STATUS
approved