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 A259186 #12 Jul 10 2015 00:36:20
%S A259186 7,13,43,31,211,157,307,757,307,1483,1723,3541,1723,5113,3907,8191,
%T A259186 3541,8011,1723,6007,5113,5113,14281,5113,14281,8011,3541,28057,20593,
%U A259186 20593,5113,37831,28057,17293,14281,8011,12433,28057,20593,14281,24181,10303,46441
%N A259186 Primes in A259184.
%C A259186 These primes are neither sorted nor uniqued. They are listed in the order found in A259184.
%H A259186 Robert Price, <a href="/A259186/b259186.txt">Table of n, a(n) for n = 1..1737</a>
%H A259186 OEIS Wiki, <a href="https://oeis.org/wiki/Cyclotomic Polynomials at x=n, n! and sigma(n)">Cyclotomic Polynomials at x=n, n! and sigma(n)</a>
%F A259186 a(n) = A259184(A259185(n)).
%p A259186 with(numtheory): A259186:=n->`if`(isprime(1 - sigma(n) + sigma(n)^2), 1 - sigma(n) + sigma(n)^2, NULL): seq(A259186(n), n=1..200); # _Wesley Ivan Hurt_, Jul 09 2015
%t A259186 Select[Table[1 - DivisorSigma[1, n] + DivisorSigma[1, n]^2, {n, 10000}], PrimeQ]
%t A259186 Select[Table[Cyclotomic[6, DivisorSigma[1, n]], {n, 10000}], PrimeQ]
%Y A259186 Cf. A000203, A259184, A259185.
%K A259186 easy,nonn
%O A259186 1,1
%A A259186 _Robert Price_, Jun 20 2015