A250195 Numbers n such that Phi(49,n) is prime, where Phi is the cyclotomic polynomial.

1, 2, 5, 62, 67, 104, 123, 138, 151, 186, 194, 233, 236, 261, 269, 306, 359, 416, 425, 439, 557, 613, 695, 705, 742, 748, 821, 832, 884, 885, 892, 902, 936, 937, 1125, 1165, 1176, 1248, 1265, 1320, 1337, 1386, 1544, 1594, 1675, 1707, 1712, 1714, 1722, 1725, 1798, 1840, 1844

Offset: 1

Author

R. J. Mathar, Jan 12 2015

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A246392.

Programs

Mathematica

Select[Range[1900], PrimeQ[Cyclotomic[49, #]] &] (* Vincenzo Librandi, Jan 17 2015 *)

PARI

{is(n)=isprime(polcyclo(49,n))};
for(n=1,1000, if(is(n), print1(n, ", "))) \\ G. C. Greubel, May 20 2018