A322916 Numbers k such that 303*2^k+1 is prime.

1, 2, 5, 8, 9, 10, 13, 17, 21, 30, 38, 93, 125, 140, 170, 178, 181, 394, 453, 588, 1161, 1221, 1573, 1665, 1745, 3613, 3661, 5750, 6002, 6198, 6393, 6764, 7209, 7514, 9444, 13034, 15277, 16070, 20042, 22970, 22977, 25674, 28438, 31040, 35137, 42410, 60285

Offset: 1

Author

Robert Price, Dec 30 2018

Keywords

• nonn
• hard

Links

• Jeppe Stig Nielsen, Table of n, a(n) for n = 1..76 (terms n = 1..68 from Robert Price)
• Ray Ballinger, Proth Search Page
• Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for 300 < k < 600
• Y. Gallot, Proth.exe: Windows Program for Finding Large Primes
• Wilfrid Keller, List of primes k.2^n - 1 for k < 300
• Eric Weisstein's World of Mathematics, Proth Prime
• Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Crossrefs

Cf. A002255, A050527.

Programs

Maple

select(n->isprime(303*2^n+1),[$1..1000]); # Muniru A Asiru, Dec 31 2018

Mathematica

Select[Range[1000], PrimeQ[303*2^# + 1] &] (* Robert Price, Dec 30 2018 *)