A323104 - OEIS

%I #10 Dec 18 2024 16:41:04

%S 2,6,18,110,186,318,398,1922,3290,4346,5042,6638,8306,59066,66758,

%T 182198,214406,260810,709350,947018,1384346,1546542,2360166

%N Numbers k such that 409*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>

%p select(k->isprime(409*2^k+1),[$1..1000]); # _Muniru A Asiru_, Jan 04 2019

%t Select[Range[1000], PrimeQ[409*2^# + 1] &]

%K nonn,more,hard

%O 1,1

%A _Robert Price_, Jan 04 2019

%E a(23) from _Jeppe Stig Nielsen_, Dec 18 2024