A032408 - OEIS

%I #39 Feb 25 2020 18:02:47

%S 3,4,6,10,16,30,36,91,94,156,382,454,643,867,1416,2656,2851,5971,6016,

%T 7260,9876,15019,43504,53827,88132,149032,153372,207571,223656,258442,

%U 344850,403164,946852,1024380,1035072,1057032,1157460,2794014

%N Numbers k such that 117*2^k+1 is prime.

%H Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>

%H Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>

%H Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a>

%H Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>

%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>

%t Select[Range[1000], PrimeQ[117*2^# + 1] & ] (* _Robert Price_, Dec 17 2018 *)

%o (PARI) is(n)=ispseudoprime(117*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn,more

%O 1,1

%A _James R. Buddenhagen_

%E Extended by _Hugo Pfoertner_, Jul 02 2003

%E a(28)-a(37) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 17 2018

%E a(38) from _Jeppe Stig Nielsen_, Feb 25 2020