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 A070521 #7 Aug 29 2019 05:23:32
%S A070521 2,7,121,5461,12207031,2612138803,38771752331201,20587884010836553,
%T A070521 1107867264956562636991,11111111111111111111111111111,
%U A070521 19194342495775048050414684129181,773238409074645649506921062192257266781,391287702091575733090747617444785169589677401
%N A070521 Value of prime(n)-th cyclotomic polynomial at n.
%F A070521 a(n) = Cyclotomic[Prime[n], n]
%e A070521 n=3: Cyclotomic[prime(3),x]=C[5,3]=[1+x+xx+xxx+xxxx,at x=3]; it is 1+3+9+27+81=121=a(3).
%t A070521 Table[Cyclotomic[Prime[w], w], {w, 1, 25}]
%o A070521 (PARI) a(n) = polcyclo(prime(n), n); \\ _Michel Marcus_, Aug 29 2019
%Y A070521 Cf. A070518-A070520.
%K A070521 nonn
%O A070521 1,1
%A A070521 _Labos Elemer_, May 02 2002
%E A070521 More terms from _Michel Marcus_, Aug 29 2019