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 A250184 #13 May 21 2018 03:25:03 %S A250184 2,3,13,14,18,31,44,59,62,75,80,104,109,145,185,213,273,282,309,321, %T A250184 337,379,399,405,411,430,452,464,470,522,535,560,566,586,593,597,653, %U A250184 654,688,702,704,727,728,744,746,780,805,806,816,822,829,846,856 %N A250184 Numbers n such that Phi(33,n) is prime, where Phi is the cyclotomic polynomial. %H A250184 G. C. Greubel, <a href="/A250184/b250184.txt">Table of n, a(n) for n = 1..10000</a> %t A250184 Select[Range[900], PrimeQ[Cyclotomic[33, #]] &] (* _Vincenzo Librandi_, Jan 17 2015 *) %o A250184 (PARI) isok(n) = isprime(polcyclo(30, n)); \\ _Michel Marcus_, Jan 17 2015 %Y A250184 Cf. A246392. %K A250184 nonn %O A250184 1,1 %A A250184 _R. J. Mathar_, Jan 12 2015