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A205796 Numbers n such that 4*17^n - 1 is prime. 0
1, 9, 33, 69, 427, 1009, 2667 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..7.

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

Adjacent sequences:  A205793 A205794 A205795 * A205797 A205798 A205799

KEYWORD

nonn

AUTHOR

José María Grau Ribas, Jan 31 2012

STATUS

approved

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Last modified January 22 19:44 EST 2020. Contains 331153 sequences. (Running on oeis4.)