login
A032462
Numbers k such that 171*2^k+1 is prime.
0
8, 9, 24, 32, 71, 117, 141, 144, 369, 393, 575, 837, 921, 1007, 3825, 3837, 18813, 21731, 25233, 36261, 57104, 128301, 299840, 404379, 714200, 717731, 910544, 1061853, 1658303
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[171*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)
PROG
(PARI) is(n)=ispseudoprime(171*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A304600 A278076 A081351 * A077599 A109097 A335770
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(22)-a(29) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
STATUS
approved