A138938 Indices k such that A019326(k)=Phi[k](8) is prime, where Phi is a cyclotomic polynomial.

1, 3, 9, 30, 42, 78, 87, 138, 189, 303, 318, 330, 408, 462, 504, 561, 1002, 1389, 1746, 1794, 2040, 2418, 2790, 3894, 4077, 4722, 6738, 10641, 14610, 14616, 15294, 16662, 18966, 19059, 26142, 27144, 28299, 31638, 33639, 39360

Offset: 1

Author

M. F. Hasler, Apr 03 2008

Keywords

• nonn

Links

• Yves Gallot, Cyclotomic polynomials and prime numbers
• Index entries for cyclotomic polynomials, values at X

Crossrefs

Cf. A019326, A138920-A138940.

Programs

Mathematica

Select[Range[1000], PrimeQ[Cyclotomic[#, 8]] &]

PARI

for( i=1,999, ispseudoprime( polcyclo(i,8)) && print1( i",")) /* use ...subst( polcyclo(i),x,8)... in PARI < 2.4.2 */

Extensions

a(17)-a(40) from Robert Price, Apr 20 2012