A323113 Numbers k such that 425*2^k+1 is prime.

7, 27, 31, 43, 79, 169, 193, 241, 511, 987, 1273, 1807, 2671, 3327, 3409, 8469, 12691, 16465, 50595, 62155, 154323, 336465, 479187, 524997, 641553, 1048563

Offset

1,1

Links

Table of n, a(n) for n=1..26.

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(425*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 05 2019

Mathematica

Select[Range[1000], PrimeQ[425*2^# + 1] &]

Crossrefs

Sequence in context: A166406 A243006 A175377 * A205861 A215446 A098948

Adjacent sequences: A323110 A323111 A323112 * A323114 A323115 A323116

Keyword

nonn,more,hard

Author

Robert Price, Jan 04 2019

Status

approved