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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. 2

%I

%S 7757430,31286970,360821505,365536215,414779430,418803000,428547690,

%T 428823900,434768475,508654155,584808795,732681630,809814510,

%U 846079035,857095380,968314215,1115279880,1187901285,1193371860,1244805450

%N 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.

%H Amiram Eldar, <a href="/A124416/b124416.txt">Table of n, a(n) for n = 1..100</a>

%t Select[15*Range[10^8], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64, 128, 256}*# + 1) &] (* _Ray Chandler_, Nov 21 2006 *)

%t 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 *)

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

%K nonn,changed

%O 1,1

%A _Artur Jasinski_, Nov 02 2006

%E Extended by _Ray Chandler_, Nov 21 2006

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Last modified April 5 03:13 EDT 2020. Contains 333238 sequences. (Running on oeis4.)