A323149 Numbers k such that 441*2^k+1 is prime.

1, 3, 4, 13, 17, 21, 47, 76, 91, 137, 167, 181, 211, 347, 353, 407, 479, 553, 591, 747, 981, 1407, 3009, 3127, 6483, 10269, 17427, 21181, 24349, 36081, 54843, 56607, 64369, 64917, 66583, 79719, 83187, 109149, 133580, 137788, 141836, 145604, 146909, 181439

Offset

1,2

Comments

The associated primes are: 883, 3529, 7057, 3612673, ... - Vincenzo Librandi, Jan 06 2019

When k is even, the associated prime is of form B^2 + 1. - Jeppe Stig Nielsen, Dec 27 2019

Links

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..56 (n=1..53 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

Maple

select(k->isprime(441*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 05 2019

Mathematica

Select[Range[1000], PrimeQ[441*2^# + 1] &]

Prog

(Magma) [n: n in [1..5000] | IsPrime(441*2^n+1)]; // Vincenzo Librandi, Jan 06 2019

Crossrefs

Sequence in context: A057570 A024853 A023857 * A291250 A205901 A302392

Adjacent sequences: A323146 A323147 A323148 * A323150 A323151 A323152

Keyword

nonn,hard

Author

Robert Price, Jan 05 2019

Status

approved