A323102 Numbers k such that 405*2^k+1 is prime.

1, 2, 4, 8, 10, 14, 32, 43, 46, 58, 80, 163, 184, 227, 262, 361, 592, 602, 623, 638, 2287, 2680, 3674, 11221, 12278, 12556, 12763, 15412, 21472, 49118, 57040, 64825, 121262, 127495, 300604, 572623, 769828, 904000, 1693765, 2099716

Offset

1,2

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

Maple

select(k->isprime(405*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 04 2019

Mathematica

Select[Range[1000], PrimeQ[405*2^# + 1] &]

Crossrefs

Sequence in context: A049422 A178215 A067925 * A331627 A102431 A076919

Adjacent sequences: A323099 A323100 A323101 * A323103 A323104 A323105

Keyword

nonn,more,hard

Author

Robert Price, Jan 04 2019

Extensions

a(40) from Jeppe Stig Nielsen, May 30 2020

Status

approved