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Primes of the form Phi(k, -4), where Phi is the cyclotomic polynomial.
1

%I #9 Nov 11 2019 13:48:40

%S 13,17,257,241,65537,61681,15790321,4278255361,4562284561,

%T 291280009243618888211558641,18446744069414584321,

%U 78919881726271091143763623681,84179842077657862011867889681,20988936657440586486151264256610222593863921,84159375948762099254554456081

%N Primes of the form Phi(k, -4), where Phi is the cyclotomic polynomial.

%H Robert Price, <a href="/A292003/b292003.txt">Table of n, a(n) for n = 1..16</a>

%H Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/papers/cyclotomic.html">Cyclotomic polynomials and prime numbers</a>

%H <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index entries for cyclotomic polynomials,values at X</a>

%t Select[Table[Cyclotomic[k,-4], {k, 0, 100}], PrimeQ[#] &]

%Y Cf. A138926.

%K nonn

%O 1,1

%A _Robert Price_, Sep 07 2017