A323043 Numbers k such that 397*2^k+1 is prime.

4, 6, 16, 24, 30, 36, 40, 52, 60, 78, 132, 204, 352, 556, 1936, 4876, 5278, 6450, 6546, 9498, 10878, 13012, 22356, 24498, 28768, 29952, 41050, 46242, 56874, 61414, 74148, 81306, 118090, 134056, 391200, 598342, 825972, 1293028, 2598796, 3859450

Offset

1,1

Links

Table of n, a(n) for n=1..40.

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

Mathematica

Select[Range[1000], PrimeQ[397*2^# + 1] &] (* Robert Price, Jan 03 2019 *)

Crossrefs

Sequence in context: A306905 A097970 A044858 * A120375 A025618 A133572

Adjacent sequences: A323040 A323041 A323042 * A323044 A323045 A323046

Keyword

nonn,more,hard

Author

Robert Price, Jan 03 2019

Extensions

a(39) from Jeppe Stig Nielsen, Jan 04 2020

a(40) from Jeppe Stig Nielsen, Dec 18 2024

Status

approved