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Numbers k such that 309*2^k+1 is prime.
1

%I #14 Dec 20 2024 10:06:21

%S 1,2,3,6,9,21,51,53,57,67,69,106,143,163,193,194,231,338,343,1197,

%T 1314,2178,2266,3401,3422,4751,5914,6097,11403,16519,24227,24447,

%U 27041,29591,41466,44459,46522,49458,55198,64177,71877,79898,102411,110503,113258

%N Numbers k such that 309*2^k+1 is prime.

%H Jeppe Stig Nielsen, <a href="/A323144/b323144.txt">Table of n, a(n) for n = 1..59</a> (terms n = 1..57 from Robert Price)

%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/riesel1a.html">List of primes k.2^n + 1 for 300 < k < 600</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 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ProthPrime.html">Proth Prime</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>

%p select(k->isprime(309*2^k+1),[$1..1000]); # _Muniru A Asiru_, Jan 05 2019

%t Select[Range[1000], PrimeQ[309*2^# + 1] &]

%K nonn,hard

%O 1,2

%A _Robert Price_, Jan 05 2019