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A322971 Numbers k such that 347*2^k+1 is prime. 1
3, 7, 15, 23, 27, 175, 259, 391, 607, 679, 863, 927, 999, 1339, 1371, 1555, 2103, 2151, 2715, 5619, 6411, 7055, 12927, 19015, 26095, 42523, 45719, 55519, 70971, 87663, 176007, 243391, 287083, 544887, 696327, 902995, 1041223, 1061675, 1218211, 1355595 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Price, Table of n, a(n) for n = 1..42

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

MAPLE

select(k->isprime(347*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 02 2019

MATHEMATICA

Select[Range[1000], PrimeQ[347*2^# + 1] &] (* Robert Price, Jan 01 2019 *)

CROSSREFS

Sequence in context: A091711 A103007 A077790 * A165469 A160160 A192122

Adjacent sequences:  A322968 A322969 A322970 * A322972 A322973 A322974

KEYWORD

nonn,hard

AUTHOR

Robert Price, Jan 01 2019

STATUS

approved

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Last modified December 10 14:27 EST 2019. Contains 329896 sequences. (Running on oeis4.)