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A032495
Numbers k such that 237*2^k+1 is prime.
0
4, 10, 52, 58, 59, 68, 82, 115, 247, 647, 2338, 2627, 4415, 8410, 17098, 38434, 42739, 59140, 100627, 104372, 127363, 137767, 173551, 234082, 243772, 585403, 1710490
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[237*2^# + 1] & ] (* Robert Price, Dec 19 2018 *)
PROG
(PARI) is(n)=ispseudoprime(237*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A151611 A351046 A208236 * A109387 A362819 A018844
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(19)-a(27) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 19 2018
STATUS
approved