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 A070527 #21 Aug 12 2023 17:15:34
%S A070527 2,3,4,7,40,59,140
%N A070527 Numbers k such that cyclotomic(k, 2^k) is a prime number.
%C A070527 No other terms below 300. - _Max Alekseyev_, May 29 2009
%C A070527 No other terms below 760. - _Lucas A. Brown_, Dec 16 2020
%e A070527 4 is a term because cyclotomic(4,16) = 1 + 16^2 = 257 is prime.
%t A070527 Do[s=Cyclotomic[n, 2^n]; If[PrimeQ[s], Print[n]], {n, 1, 1000}]
%t A070527 Select[Range[150],PrimeQ[Cyclotomic[#,2^#]]&] (* _Harvey P. Dale_, Aug 12 2023 *)
%o A070527 (PARI) isok(k) = isprime(polcyclo(k, 2^k)); \\ _Michel Marcus_, Dec 17 2020
%Y A070527 Cf. A070518-A070526.
%K A070527 more,nonn
%O A070527 1,1
%A A070527 _Labos Elemer_, May 02 2002
%E A070527 One more term from _Max Alekseyev_, May 29 2009