A050525 Primes of the form 11*2^k - 1.

43, 738197503, 12384898975268863, 198158383604301823, 935776509032580774524280170437362581503, 239558786312340678278215723631964820865023, 1243860333603982568026641440523014635142548663400435746517610765710004322303

Offset: 1

Author

N. J. A. Sloane, Dec 29 1999

Keywords

• nonn
• nice

Links

• Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime.

Crossrefs

See A001772 for more terms.

Cf. A086225.

Programs

Mathematica

Select[11 2^Range[0,250]-1,PrimeQ]  (* Harvey P. Dale, Mar 30 2011 *)

Formula

a(n) = A086225(A001772(n)). - Elmo R. Oliveira, May 04 2025