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 A250175 #29 May 21 2018 03:24:25 %S A250175 2,3,11,17,23,43,46,52,53,61,62,78,84,88,89,92,99,108,123,124,141,146, %T A250175 154,156,158,163,170,171,182,187,202,217,219,221,229,233,238,248,249, %U A250175 253,264,274,275,278,283,285,287,291,296,302,309,314,315,322,325,342,346,353,356,366,368,372,377,380,384,394,404,406,411,420,425 %N A250175 Numbers n such that Phi_15(n) is prime, where Phi is the cyclotomic polynomial. %H A250175 G. C. Greubel, <a href="/A250175/b250175.txt">Table of n, a(n) for n = 1..10000</a> %t A250175 Select[Range[600], PrimeQ[Cyclotomic[15, #]] &] (* _Vincenzo Librandi_, Jan 16 2015 *) %o A250175 (PARI) isok(n) = isprime(polcyclo(15, n)); \\ _Michel Marcus_, Jan 16 2015 %Y A250175 Cf. A008864 (1), A006093 (2), A002384 (3), A005574 (4), A049409 (5), A055494(6), A100330 (7), A000068 (8), A153439 (9), A246392 (10), A162862(11), A246397 (12), A217070 (13), A006314 (16), A217071 (17), A164989(18), A217072 (19), A217073 (23), A153440 (27), A217074 (29), A217075(31), A006313 (32), A097475 (36), A217076 (37), A217077 (41), A217078(43), A217079 (47), A217080 (53), A217081 (59), A217082 (61), A006315(64), A217083 (67), A217084 (71), A217085 (73), A217086 (79), A153441(81), A217087 (83), A217088 (89), A217089 (97), A006316 (128), A153442(243), A056994 (256), A056995 (512), A057465 (1024), A057002 (2048), A088361 (4096), A088362 (8192), A226528 (16384), A226529 (32768), A226530(65536). %K A250175 nonn %O A250175 1,1 %A A250175 _Eric Chen_, Dec 24 2014 %E A250175 More terms from _Vincenzo Librandi_, Jan 16 2015