A322945 - OEIS

%I #13 Feb 16 2025 08:33:57

%S 2,8,16,26,34,112,182,226,304,782,6886,36422,647786,1289306,2862962

%N Numbers k such that 307*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/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="https://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>

%t Select[Range[1000], PrimeQ[307*2^# + 1] &] (* _Robert Price_, Dec 31 2018 *)

%Y Cf. A002255, A050527.

%K nonn,more,hard,changed

%O 1,1

%A _Robert Price_, Dec 31 2018

%E a(15) from _Jeppe Stig Nielsen_, May 30 2020