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 A258355 #7 Jun 20 2015 14:43:04 %S A258355 0,1,2,98,775 %N A258355 Numbers n such that cyclotomic polynomial value Phi(9,n!) is prime. %C A258355 All values correspond to certified primes. %C A258355 a(6) > 5944. %e A258355 2 is in the sequence because Phi(9,2!) = 1 + 2^3 + 2^6 = 73 is prime. %t A258355 Select[Range[0, 5944], PrimeQ[Cyclotomic[9, #!]] &] %Y A258355 Cf. A002981, A002982, A046029, A200906. %K A258355 nonn,more %O A258355 1,3 %A A258355 _Robert Price_, May 27 2015