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 A088856 #17 Feb 16 2025 08:32:51
%S A088856 2,3,7,127,8599
%N A088856 Primes p such that cyclotomic(p,p-1) is prime.
%C A088856 Some of the larger entries may only correspond to probable primes.
%C A088856 For p > 2, these are numbers p such that ((p-1)^p - 1)/(p-2) is prime. - _Thomas Ordowski_, Sep 02 2021
%H A088856 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CyclotomicPolynomial.html">Cyclotomic Polynomial</a>
%F A088856 a(n) = A101753(n) + 1. - _Thomas Ordowski_, Sep 02 2021
%t A088856 lst={}; Do[p=Prime[n]; If[PrimeQ[Cyclotomic[p, p-1]], AppendTo[lst, p]], {n, 400}]; lst
%o A088856 (PARI) isok(p) = isprime(p) && isprime(polcyclo(p, p-1)); \\ _Michel Marcus_, Sep 02 2021
%Y A088856 Cf. A070519, A070525, A101753.
%K A088856 more,nonn
%O A088856 1,1
%A A088856 _T. D. Noe_, Nov 23 2003