OFFSET
1,1
COMMENTS
It is easily proved that if 2^m-3 is prime then 2^(m-1)*(2^m-3) is in the sequence. - Farideh Firoozbakht, Feb 12 2008
No other terms up to 5*10^9. - Michel Marcus, Mar 10 2026
PROG
(PARI) for(n=1, 10^8, if(sigma(n)==2*n+omega(n), print1(n, ", ")))
(PARI) isok(k) = my(f=factor(k)); sigma(f)==2*k+omega(k); \\ Michel Marcus, Mar 10 2026
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Jason Earls, Aug 17 2001
STATUS
approved