A032420 - OEIS

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A032420

Numbers k such that 141*2^k+1 is prime.

3

1, 3, 5, 7, 8, 12, 15, 20, 31, 33, 37, 41, 61, 65, 91, 93, 103, 117, 133, 137, 141, 160, 291, 303, 343, 488, 535, 555, 556, 640, 756, 897, 917, 1745, 1805, 2053, 2372, 3375, 5952, 9612, 15717, 18432, 25593, 29212, 31004, 31135, 32192, 32287, 43477, 44901

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..81 (terms n = 1..78 from Robert Price)

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

MAPLE

select(k->isprime(141*2^k+1), [$0..400])[]; # Muniru A Asiru, Dec 18 2018

MATHEMATICA

Select[Range[1000], PrimeQ[141*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

PROG

(PARI) is(n)=ispseudoprime(141*2^n+1) \\ Charles R Greathouse IV, Jun 07 2017

CROSSREFS

Sequence in context: A228075 A309405 A354300 * A127458 A039003 A229860

Adjacent sequences: A032417 A032418 A032419 * A032421 A032422 A032423

KEYWORD

nonn

AUTHOR

James R. Buddenhagen

EXTENSIONS

a(51)-a(78) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

STATUS

approved