A217071 - OEIS

A217071

Numbers n such that (n^17-1)/(n-1) is prime.

2, 11, 20, 21, 28, 31, 55, 57, 62, 84, 87, 97, 107, 109, 129, 147, 149, 157, 160, 170, 181, 189, 191, 207, 241, 247, 251, 274, 295, 297, 315, 327, 335, 349, 351, 355, 364, 365, 368, 379, 383, 410, 419, 423, 431, 436, 438, 466, 472, 506, 513, 527, 557, 571, 597

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Range[2, 1000], PrimeQ[(#^17 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)

PROG

(Magma) [n: n in [2..1000] |IsPrime((n^17 - 1) div (n - 1))]; // Vincenzo Librandi, Sep 28 2012

(PARI) is(n)=isprime((n^17-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

CROSSREFS

Cf. A002384, A049409, A100330, A162862, A217070-A217089.