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A032469 Numbers k such that 185*2^k+1 is a prime. 0
3, 21, 497, 707, 933, 963, 1187, 1337, 2633, 2993, 3963, 4947, 5177, 11883, 98627, 235673, 375723, 384747, 681393, 2235003 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..20.

Ray Ballinger, Proth Search Page

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

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 a prime

MAPLE

select(k->isprime(185*2^k+1), [$0..1000]); # Muniru A Asiru, Dec 18 2018

MATHEMATICA

Select[Range[1000], PrimeQ[185*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)

CROSSREFS

Sequence in context: A336578 A285380 A139224 * A006927 A014375 A135748

Adjacent sequences:  A032466 A032467 A032468 * A032470 A032471 A032472

KEYWORD

nonn,hard,more

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(16)-a(19) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018

a(20) from Jeppe Stig Nielsen, Apr 19 2020

STATUS

approved

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Last modified May 10 22:16 EDT 2021. Contains 343780 sequences. (Running on oeis4.)