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A032501
Numbers k such that 249*2^k+1 is prime.
1
1, 2, 3, 6, 7, 10, 14, 15, 23, 34, 43, 50, 59, 79, 111, 114, 127, 142, 143, 145, 154, 159, 181, 187, 342, 474, 490, 510, 766, 789, 843, 1062, 1370, 1711, 2070, 5007, 5250, 5394, 8483, 8587, 8871, 8929, 9682, 11146, 12402, 13587, 14226, 15143, 20719, 21262
OFFSET
1,2
LINKS
MATHEMATICA
Select[Range[1000], PrimeQ[249*2^# + 1] & ] (* Robert Price, Dec 20 2018 *)
PROG
(PARI) is(n)=ispseudoprime(249*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A257678 A351554 A002038 * A240212 A333551 A093677
KEYWORD
nonn,hard
EXTENSIONS
a(50)-a(78) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 20 2018
STATUS
approved