%I #20 Nov 17 2015 09:21:59
%S 2,17,1297,331777,1503561738404723998944447273369600000001
%N Primes of the form Phi(8,n!), where Phi is the cyclotomic polynomial.
%C a(6) is 730 digits.
%H OEIS Wiki, <a href="https://oeis.org/wiki/Cyclotomic Polynomials at x=n, n! and sigma(n)">Cyclotomic Polynomials at x=n, n! and sigma(n)</a>
%t Select[Table[Cyclotomic[8, n!], {n, 0, 200}], PrimeQ]
%o (PARI) for(n=1, 500, if(isprime(k=polcyclo(8, n!)), print1(k", "))) \\ _Altug Alkan_, Nov 16 2015
%Y Cf. A123865, A200906, A259264, A259265, A260478.
%K nonn
%O 1,1
%A _Robert Price_, Aug 28 2015