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A205796
Numbers n such that 4*17^n - 1 is prime.
0
1, 9, 33, 69, 427, 1009, 2667
OFFSET
1,2
MATHEMATICA
Table[If[PrimeQ[4*17^n-1], Print[n]; n], {n, 1, 20000}]
PROG
(PARI) is(n)=ispseudoprime(4*17^n-1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A180431 (numbers n such that 4*17^n + 1 is prime).
Cf. A205521 (numbers n such that 4*11^n - 1 is prime).
Cf. A046865 (numbers n such that 4*5^n - 1 is prime).
Cf. A005540 (numbers n such that 4*3^n - 1 is prime).
Sequence in context: A145923 A092562 A103602 * A081585 A227221 A273316
KEYWORD
nonn
AUTHOR
STATUS
approved