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Numbers k such that 387*2^k+1 is prime.
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%I #4 Jan 03 2019 13:27:27

%S 2,7,15,27,28,60,67,82,88,122,179,202,235,298,519,655,2712,4132,5018,

%T 9378,9688,17080,21367,23127,61803,109408,143095,143440,285780,867355,

%U 1752919,1930200

%N Numbers k such that 387*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[387*2^# + 1] &] (* _Robert Price_, Jan 03 2019 *)

%K nonn,more,hard

%O 1,1

%A _Robert Price_, Jan 03 2019