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 A019322 #15 Feb 26 2024 09:16:54
%S A019322 4,3,5,21,17,341,13,5461,257,4161,205,1398101,241,22369621,3277,49981,
%T A019322 65537,5726623061,4033,91625968981,61681,12783421,838861,
%U A019322 23456248059221,65281,1100586419201,13421773,68719738881
%N A019322 Cyclotomic polynomials at x=4.
%H A019322 Paolo Xausa, <a href="/A019322/b019322.txt">Table of n, a(n) for n = 0..1000</a>
%H A019322 <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index entries for cyclotomic polynomials, values at X</a>
%p A019322 with(numtheory,cyclotomic); f := n->subs(x=4,cyclotomic(n,x)); seq(f(i),i=0..64);
%t A019322 Join[{4}, Cyclotomic[Range[50], 4]] (* _Paolo Xausa_, Feb 26 2024 *)
%K A019322 nonn
%O A019322 0,1
%A A019322 _Simon Plouffe_