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A032488
Numbers k such that 223*2^k+1 is prime.
1
8, 10, 22, 44, 58, 62, 68, 82, 100, 104, 118, 230, 260, 440, 446, 512, 700, 892, 932, 1240, 1456, 2438, 4982, 5090, 6496, 14678, 17944, 23786, 27838, 39866, 46322, 52358, 61700, 68584, 78244, 180410, 397096, 404962, 693656, 803446, 871438, 1065400, 1356316
OFFSET
1,1
MATHEMATICA
Select[Range[1000], PrimeQ[223*2^# + 1] & ] (* Robert Price, Dec 19 2018 *)
PROG
(PARI) is(n)=ispseudoprime(223*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A292999 A374111 A216047 * A102844 A303199 A097543
KEYWORD
nonn,hard
AUTHOR
EXTENSIONS
a(36)-a(43) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 19 2018
STATUS
approved