A323033 Numbers k such that 381*2^k+1 is prime.

3, 15, 17, 20, 21, 41, 44, 51, 113, 140, 179, 219, 249, 323, 461, 521, 671, 680, 692, 695, 716, 809, 825, 887, 897, 1055, 1439, 1641, 2873, 4103, 4593, 6912, 9551, 13472, 21131, 23403, 101225, 104471, 135993, 163931, 169824, 182969, 224085, 273672, 287543

Offset

1,1

Links

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..57 (terms n = 1..55 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(381*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 02 2019

Mathematica

Select[Range[1000], PrimeQ[381*2^# + 1] &] (* Robert Price, Jan 02 2019 *)

Crossrefs

Sequence in context: A029476 A154317 A291122 * A365371 A080705 A032921

Adjacent sequences: A323030 A323031 A323032 * A323034 A323035 A323036

Keyword

nonn,hard

Author

Robert Price, Jan 02 2019

Status

approved