A124515 Numbers k for which 2*k-1, 4*k-1, 8*k-1, 16*k-1, 32*k-1, 64*k-1, 128*k-1 and 256*k-1 are primes.

9549960, 26277285, 42932385, 85864770, 99239790, 113183070, 152596290, 172159515, 198479580, 237059175, 287482065, 305192580, 342533490, 382203030, 542591115, 563002110, 597825570, 686106720, 742227135, 786875025, 1135145760

Offset: 1

Author

Artur Jasinski, Nov 04 2006

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A006254, A124485, A124493, A124494, A124017, A125113, A124514, A124516.

Programs

Mathematica

Select[15*Range[76000000], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64, 128, 256}*# - 1) &] (* Ray Chandler, Nov 22 2006 *)

Extensions

Extended by Ray Chandler, Nov 22 2006