A032422 Numbers k such that 145*2^k+1 is prime.

6, 16, 28, 70, 76, 250, 276, 312, 562, 636, 1366, 1552, 1968, 7000, 7312, 7548, 7852, 8116, 16306, 18868, 20518, 23676, 27400, 75858, 207880, 1233286, 2621020

Offset

1,1

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 k < 300

Y. Gallot, Proth.exe: Windows Program for Finding Large Primes

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Mathematica

Select[Range[1000], PrimeQ[145*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

Prog

(PARI) is(n)=ispseudoprime(145*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A201020 A088818 A346620 * A164052 A264938 A350011

Adjacent sequences: A032419 A032420 A032421 * A032423 A032424 A032425

Keyword

nonn,more

Author

James R. Buddenhagen

Extensions

a(25)-a(26) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

a(27) from Jeppe Stig Nielsen, Mar 12 2020

Status

approved