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A032465 Numbers k such that 177*2^k+1 is prime. 1
2, 4, 6, 12, 16, 20, 23, 32, 38, 48, 54, 60, 100, 116, 118, 119, 140, 150, 163, 170, 190, 244, 271, 294, 299, 320, 334, 414, 439, 442, 468, 724, 794, 842, 864, 1032, 1750, 2050, 3980, 4010, 4756, 5096, 5963, 5966, 6836, 14160, 16748, 16844, 19814, 25398 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The subsequence of prime values starts 2, 23, 163, 271, 439, 798443, ... - Muniru A Asiru, Apr 29 2019
LINKS
Jeppe Stig Nielsen, Table of n, a(n) for n = 1..74 (terms n = 1..73 from Robert Price)
Ray Ballinger, Proth Search Page
Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
MAPLE
select(k->isprime(177*2^k+1), [$0..1000]); # Muniru A Asiru, Dec 18 2018
MATHEMATICA
Select[Range[1000], PrimeQ[177*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)
PROG
(PARI) is(n)=ispseudoprime(177*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A019280 A090748 A188047 * A089395 A089699 A089696
KEYWORD
nonn,hard
AUTHOR
EXTENSIONS
a(51)-a(73) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
STATUS
approved

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Last modified July 16 10:27 EDT 2024. Contains 374345 sequences. (Running on oeis4.)