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Primes p such that cyclotomic(p,p-1) is prime.
2

%I #16 Sep 02 2021 08:20:30

%S 2,3,7,127,8599

%N Primes p such that cyclotomic(p,p-1) is prime.

%C Some of the larger entries may only correspond to probable primes.

%C For p > 2, these are numbers p such that ((p-1)^p - 1)/(p-2) is prime. - _Thomas Ordowski_, Sep 02 2021

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CyclotomicPolynomial.html">Cyclotomic Polynomial</a>

%F a(n) = A101753(n) + 1. - _Thomas Ordowski_, Sep 02 2021

%t lst={}; Do[p=Prime[n]; If[PrimeQ[Cyclotomic[p, p-1]], AppendTo[lst, p]], {n, 400}]; lst

%o (PARI) isok(p) = isprime(p) && isprime(polcyclo(p, p-1)); \\ _Michel Marcus_, Sep 02 2021

%Y Cf. A070519, A070525, A101753.

%K more,nonn

%O 1,1

%A _T. D. Noe_, Nov 23 2003