Numbers of the form (4^k - 1)/3 whose greatest prime divisor is of the form 2^q - 1 or 2^q + 1.
A187063
Numbers of the form (4^k - 1)/3 whose greatest prime divisor is of the form 2^q - 1 or 2^q + 1.
Terms
- a(0) =5a(1) =21a(2) =85a(3) =341a(4) =5461a(5) =21845a(6) =22369621a(7) =89478485a(8) =1431655765a(9) =5726623061a(10) =91625968981
External references
- oeis: A187063