A323042 Numbers k such that 395*2^k+1 is prime.

5, 11, 23, 41, 221, 485, 839, 3029, 6479, 15455, 16715, 38399, 38525, 38645, 167501, 185571, 505679, 649445, 764369, 797849, 1106091, 1309751, 1447971, 1480715, 1538975

Offset

1,1

Links

Table of n, a(n) for n=1..25.

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[395*2^# + 1] &] (* Robert Price, Jan 03 2019 *)

Crossrefs

Sequence in context: A262284 A118439 A343711 * A210731 A295959 A156109

Adjacent sequences: A323039 A323040 A323041 * A323043 A323044 A323045

Keyword

nonn,more,hard

Author

Robert Price, Jan 03 2019

Status

approved