A323109 Numbers k such that 419*2^k+1 is prime.

1, 7, 11, 19, 53, 91, 133, 187, 211, 263, 281, 331, 437, 793, 1151, 3689, 6547, 13771, 14749, 32009, 32843, 46223, 79801, 169463, 180733, 463079, 2552363

Offset

1,2

Links

Table of n, a(n) for n=1..27.

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(419*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 04 2019

Mathematica

Select[Range[1000], PrimeQ[419*2^# + 1] &]

Crossrefs

Sequence in context: A285016 A162857 A307965 * A023267 A319224 A282037

Adjacent sequences: A323106 A323107 A323108 * A323110 A323111 A323112

Keyword

nonn,more,hard

Author

Robert Price, Jan 04 2019

Extensions

a(27) from Jeppe Stig Nielsen, Jan 04 2020

Status

approved