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 A211874 #14 Feb 21 2013 16:05:12 %S A211874 2,7,13,61,73,547,757,1093,4561,6481,368089,398581,530713,797161, %T A211874 42521761,47763361,2413941289,23535794707,282429005041,374857981681, %U A211874 144542918285300809,150094634909578633,13490012358249728401,82064241848634269407 %N A211874 Primes of the form Phi_k(3), the k-th cyclotomic polynomial evaluated at 3. %t A211874 Sort[Select[Cyclotomic[Range[1000], 3], PrimeQ]] %Y A211874 Primes in A019321. %Y A211874 Cf. A138933, A072226, A153601. %K A211874 nonn %O A211874 1,1 %A A211874 _Alexander Gruber_, Feb 12 2013