A124416 Numbers k such that 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.

7757430, 31286970, 360821505, 365536215, 414779430, 418803000, 428547690, 428823900, 434768475, 508654155, 584808795, 732681630, 809814510, 846079035, 857095380, 968314215, 1115279880, 1187901285, 1193371860, 1244805450

Offset: 1

Author

Artur Jasinski, Nov 02 2006

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A005097, A123998, A124041, A124412-A124417.

Programs

Mathematica

Select[15*Range[10^8], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64, 128, 256}*# + 1) &] (* Ray Chandler, Nov 21 2006 *)
Select[15*Range[83*10^6],AllTrue[#*2^Range[8]+1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 23 2020 *)

Extensions

Extended by Ray Chandler, Nov 21 2006