

A032457


Numbers k such that 161*2^k+1 is prime.


0



3, 5, 11, 13, 51, 53, 63, 71, 103, 179, 205, 267, 351, 589, 719, 1453, 3703, 7935, 10851, 15151, 16013, 20319, 65475, 66083, 105269, 181059, 186347, 319875, 1057743, 1668927, 1754223, 2142431
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Table of n, a(n) for n=1..32.
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^n1 (or k*2^n+1) is prime


MATHEMATICA

Select[Range[1000], PrimeQ[161*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)


PROG

(PARI) is(n)=ispseudoprime(161*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017


CROSSREFS

Sequence in context: A089251 A147568 A006794 * A122564 A162876 A162875
Adjacent sequences: A032454 A032455 A032456 * A032458 A032459 A032460


KEYWORD

nonn,hard,more


AUTHOR

N. J. A. Sloane.


EXTENSIONS

a(25)a(31) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
a(32) from Jeppe Stig Nielsen, May 30 2020


STATUS

approved



