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A322922 Numbers k such that 305*2^k+1 is prime. 0
3, 7, 21, 23, 29, 35, 53, 87, 91, 95, 115, 165, 179, 233, 367, 419, 609, 791, 2937, 3713, 4087, 5071, 6497, 30011, 30783, 32861, 48299, 60155, 143623, 293525, 465959, 567161, 975215, 1024223, 1106333, 1285643, 1597089, 2233655, 2733989, 2840155 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

MATHEMATICA

Select[Range[1000], PrimeQ[305*2^# + 1] &] (* Robert Price, Dec 30 2018 *)

CROSSREFS

Cf. A002255, A050527.

Sequence in context: A196038 A180097 A065496 * A018479 A335411 A331782

Adjacent sequences:  A322919 A322920 A322921 * A322923 A322924 A322925

KEYWORD

nonn,more,hard

AUTHOR

Robert Price, Dec 30 2018

EXTENSIONS

a(38)-a(39) from Jeppe Stig Nielsen, Dec 27 2019

a(40) from Jeppe Stig Nielsen, Feb 05 2020

STATUS

approved

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Last modified June 22 11:59 EDT 2021. Contains 345375 sequences. (Running on oeis4.)