A217081 Numbers n such that (n^59-1)/(n-1) is prime.

19, 70, 102, 116, 126, 188, 209, 257, 294, 359, 451, 461, 468, 470, 638, 653, 710, 762, 766, 781, 824, 901, 939, 964, 995, 1036, 1047, 1098, 1150, 1211, 1234, 1243, 1256, 1278, 1389, 1401, 1422, 1436, 1454, 1492, 1523, 1639, 1703, 1705, 1826, 1913, 1915, 1978

Offset: 1

Author

Tim Johannes Ohrtmann, Sep 26 2012

Keywords

• nonn
• easy

Links

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

Crossrefs

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

Programs

Magma

[n: n in [2..2000] |IsPrime((n^59 - 1) div (n - 1))]; // Vincenzo Librandi, Sep 28 2012

Mathematica

Select[Range[2, 2000], PrimeQ[(#^59 - 1)/(# - 1)] &] (* T. D. Noe, Sep 26 2012 *)

PARI

is(n)=isprime((n^59-1)/(n-1)) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

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