This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A217071 #20 Jul 08 2025 15:01:24 %S A217071 2,11,20,21,28,31,55,57,62,84,87,97,107,109,129,147,149,157,160,170, %T A217071 181,189,191,207,241,247,251,274,295,297,315,327,335,349,351,355,364, %U A217071 365,368,379,383,410,419,423,431,436,438,466,472,506,513,527,557,571,597 %N A217071 Numbers k such that (k^17-1)/(k-1) is prime. %H A217071 Vincenzo Librandi, <a href="/A217071/b217071.txt">Table of n, a(n) for n = 1..1000</a> %t A217071 Select[Range[2, 1000], PrimeQ[(#^17 - 1)/(# - 1)] &] (* _T. D. Noe_, Sep 26 2012 *) %o A217071 (Magma) [n: n in [2..1000] |IsPrime((n^17 - 1) div (n - 1))]; // _Vincenzo Librandi_, Sep 28 2012 %o A217071 (PARI) is(n)=isprime((n^17-1)/(n-1)) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A217071 Cf. A002384, A049409, A100330, A162862, A217070-A217089. %K A217071 nonn,easy %O A217071 1,1 %A A217071 _Tim Johannes Ohrtmann_, Sep 26 2012 %E A217071 More terms from _T. D. Noe_, Sep 26 2012