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A323040 Numbers k such that 391*2^k+1 is prime. 0

%I

%S 4,20,28,40,88,92,328,1052,1420,2888,3944,5888,22544,154912,716668

%N Numbers k such that 391*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="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>

%t Select[Range[1000], PrimeQ[391*2^# + 1] &] (* _Robert Price_, Jan 03 2019 *)

%K nonn,more,hard

%O 1,1

%A _Robert Price_, Jan 03 2019

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Last modified January 20 14:17 EST 2021. Contains 340302 sequences. (Running on oeis4.)