A050524 Primes of the form 9*2^n-1.

17, 71, 1151, 73727, 294911, 18874367, 79164837199871, 83010348331692982271, 5704427701027032306735164424191, 5841333965851681082096808370372607, 6576757367989063131916581747223273588451696443391

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 A002236 for more terms.

Programs

Mathematica

Select[9 2^Range[0,160]-1,PrimeQ]  (* Harvey P. Dale, Apr 13 2011 *)