A323114 Numbers k such that 427*2^k+1 is prime.

2, 4, 6, 8, 12, 20, 22, 56, 66, 94, 136, 142, 174, 186, 200, 286, 352, 362, 512, 582, 842, 1056, 1080, 1144, 1242, 1810, 4802, 5106, 6914, 12982, 16760, 19958, 20108, 22194, 23512, 29636, 42816, 66178, 70624, 81390, 129958, 184046, 278876, 343432, 396612

Offset

1,1

Links

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..60 (terms n = 1..54 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(427*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 05 2019

Mathematica

Select[Range[1000], PrimeQ[427*2^# + 1] &]

Prog

(Python)
from sympy.ntheory.primetest import isprime
for n in range(1, 1000):
    if isprime(427*2**n+1):
        print(n, end=', ') # Stefano Spezia, Jan 05 2019

Crossrefs

Sequence in context: A057335 A126907 A292994 * A362231 A118563 A228515

Adjacent sequences: A323111 A323112 A323113 * A323115 A323116 A323117

Keyword

nonn,hard,changed

Author

Robert Price, Jan 04 2019

Status

approved