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 A292004 #9 Nov 11 2019 13:48:45
%S A292004 7,61,13,547,73,398581,1093,757,23535794707,6481,797161,4561,
%T A292004 374857981681,530713,42521761,368089,82064241848634269407,47763361,
%U A292004 105919308797935444986721,2413941289,282429005041,56495392933101222275861053369,150094634909578633
%N A292004 Primes of the form Phi(k, -3), where Phi is the cyclotomic polynomial.
%H A292004 Robert Price, <a href="/A292004/b292004.txt">Table of n, a(n) for n = 1..38</a>
%H A292004 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/papers/cyclotomic.html">Cyclotomic polynomials and prime numbers</a>
%H A292004 <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index entries for cyclotomic polynomials,values at X</a>
%t A292004 Select[Table[Cyclotomic[k,-3], {k, 0, 100}], PrimeQ[#] &]
%Y A292004 Cf. A138927.
%K A292004 nonn
%O A292004 1,1
%A A292004 _Robert Price_, Sep 07 2017