

A032410


Numbers k such that 121*2^k+1 is prime.


1



8, 12, 44, 84, 96, 228, 264, 320, 732, 788, 1808, 7928, 12264, 37784, 59196, 91112, 112208, 168716, 251184, 264632, 272052, 513020, 636564, 674360
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OFFSET

1,1


COMMENTS

9584444 is also a term (cf. PrimeGrid, 2020).  Felix FrÃ¶hlich, Dec 10 2020


LINKS

Table of n, a(n) for n=1..24.
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
PrimeGrid, Announcement of 9584444, 2020.
Index entries for sequences of n such that k*2^n1 (or k*2^n+1) is prime


MATHEMATICA

Select[Range[1000], PrimeQ[121*2^# + 1] & ] (* Robert Price, Dec 17 2018 *)


PROG

(PARI) is(n)=ispseudoprime(121*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017


CROSSREFS

Cf. A050586.
Sequence in context: A281663 A092179 A269726 * A077101 A229497 A009926
Adjacent sequences: A032407 A032408 A032409 * A032411 A032412 A032413


KEYWORD

nonn,hard,more


AUTHOR

James R. Buddenhagen


EXTENSIONS

Extended by Hugo Pfoertner, Jul 02 2003
a(20)a(24) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 17 2018


STATUS

approved



