A205796 Numbers n such that 4*17^n - 1 is prime.

1, 9, 33, 69, 427, 1009, 2667

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