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 A292003 #9 Nov 11 2019 13:48:40
%S A292003 13,17,257,241,65537,61681,15790321,4278255361,4562284561,
%T A292003 291280009243618888211558641,18446744069414584321,
%U A292003 78919881726271091143763623681,84179842077657862011867889681,20988936657440586486151264256610222593863921,84159375948762099254554456081
%N A292003 Primes of the form Phi(k, -4), where Phi is the cyclotomic polynomial.
%H A292003 Robert Price, <a href="/A292003/b292003.txt">Table of n, a(n) for n = 1..16</a>
%H A292003 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/papers/cyclotomic.html">Cyclotomic polynomials and prime numbers</a>
%H A292003 <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index entries for cyclotomic polynomials,values at X</a>
%t A292003 Select[Table[Cyclotomic[k,-4], {k, 0, 100}], PrimeQ[#] &]
%Y A292003 Cf. A138926.
%K A292003 nonn
%O A292003 1,1
%A A292003 _Robert Price_, Sep 07 2017