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A032490
Numbers k such that 227*2^k+1 is prime.
0
11, 15, 35, 51, 83, 87, 99, 183, 4619, 4659, 6939, 7503, 10647, 13007, 18459, 19599, 26363, 43719, 53171, 140679, 249599, 308139, 797603, 1542323, 1786779
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[227*2^# + 1] & ] (* Robert Price, Dec 19 2018 *)
PROG
(PARI) is(n)=ispseudoprime(227*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A316643 A373610 A097512 * A068483 A357626 A241679
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(20)-a(25) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 19 2018
STATUS
approved