A217089 Numbers n such that (n^97-1)/(n-1) is prime.

12, 90, 104, 234, 271, 339, 420, 421, 428, 429, 464, 805, 909, 934, 1054, 1114, 1116, 1128, 1144, 1159, 1193, 1364, 1788, 2086, 2215, 2254, 2448, 2461, 2593, 2595, 2771, 2787, 2829, 2859, 2952, 3029, 3075, 3144, 3250, 3265, 3268, 3301, 3701, 3752, 3875, 4026

Offset: 1

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..300

Crossrefs

Cf. A002384, A049409, A100330, A162862, A217070-A217088.

Programs

Mathematica

Select[Range[2, 1000], PrimeQ[(#^97 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)

PARI

is(n)=isprime((n^97-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

More terms from T. D. Noe, Sep 26 2012