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 A217073 #18 Jul 08 2025 15:00:55 %S A217073 10,40,82,113,127,141,170,257,275,287,295,315,344,373,442,468,609,634, %T A217073 646,663,671,710,819,834,857,884,894,904,992,997,1060,1069,1077,1120, %U A217073 1143,1190,1232,1253,1261,1280,1291,1347,1407,1436,1448,1483,1514,1570,1642 %N A217073 Numbers k such that (k^23-1)/(k-1) is prime. %H A217073 Vincenzo Librandi, <a href="/A217073/b217073.txt">Table of n, a(n) for n = 1..1000</a> %t A217073 Select[Range[2, 1700], PrimeQ[(#^23 - 1)/(# - 1)] &] (* _T. D. Noe_, Sep 26 2012 *) %o A217073 (Magma) [n: n in [2..1700] |IsPrime((n^23 - 1) div (n - 1))]; // _Vincenzo Librandi_, Sep 28 2012 %o A217073 (PARI) is(n)=isprime((n^23-1)/(n-1)) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A217073 Cf. A002384, A049409, A100330, A162862, A217070-A217089. %K A217073 nonn,easy %O A217073 1,1 %A A217073 _Tim Johannes Ohrtmann_, Sep 26 2012 %E A217073 More terms from _T. D. Noe_, Sep 26 2012