Primes p of the form sigma(2^k + 1) - 1 for some k >= 0.
A268130
Primes p of the form sigma(2^k + 1) - 1 for some k >= 0.
Terms
- a(0) =2a(1) =3a(2) =5a(3) =17a(4) =47a(5) =83a(6) =257a(7) =1301a(8) =65537a(9) =174767a(10) =5048231a(11) =51322664447
External references
- oeis: A268130