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 A217074 #17 Jul 08 2025 14:35:33 %S A217074 6,40,65,70,114,151,221,229,268,283,398,451,460,519,554,587,627,628, %T A217074 659,687,699,859,884,915,943,974,986,1101,1120,1159,1176,1212,1223, %U A217074 1297,1312,1322,1337,1390,1409,1415,1446,1477,1508,1592,1636,1691,1800,1802,1803 %N A217074 Numbers k such that (k^29-1)/(k-1) is prime. %H A217074 Vincenzo Librandi, <a href="/A217074/b217074.txt">Table of n, a(n) for n = 1..1000</a> %t A217074 Select[Range[2, 2000], PrimeQ[(#^29 - 1)/(# - 1)] &] (* _T. D. Noe_, Sep 26 2012 *) %o A217074 (Magma) [n: n in [2..2000] |IsPrime((n^29 - 1) div (n - 1))]; // _Vincenzo Librandi_, Sep 28 2012 %o A217074 (PARI) is(n)=isprime((n^29-1)/(n-1)) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A217074 Cf. A002384, A049409, A100330, A162862, A217070-A217089. %K A217074 nonn,easy %O A217074 1,1 %A A217074 _Tim Johannes Ohrtmann_, Sep 26 2012 %E A217074 More terms from _T. D. Noe_, Sep 26 2012