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

1,1

Links

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

Mathematica

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

Crossrefs

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

Sequence in context: A270994 A162030 A184570 * A075009 A186627 A203660

Adjacent sequences: A124512 A124513 A124514 * A124516 A124517 A124518

Keyword

nonn

Author

Artur Jasinski, Nov 04 2006

Extensions

Extended by Ray Chandler, Nov 22 2006

Status

approved