A138933 Indices k such that A019321(k)=Phi[k](3) is prime, where Phi is a cyclotomic polynomial.

1, 3, 6, 7, 9, 10, 12, 13, 14, 15, 21, 24, 26, 33, 36, 40, 46, 60, 63, 70, 71, 72, 86, 103, 108, 130, 132, 143, 145, 154, 161, 236, 255, 261, 276, 279, 287, 304, 364, 430, 464, 513, 528, 541, 562, 665, 672, 680, 707, 718, 747, 760, 782, 828, 875, 892, 974, 984

Offset

1,2

Links

Robert Price, Table of n, a(n) for n = 1..167

Yves Gallot, Cyclotomic polynomials and prime numbers

Index entries for cyclotomic polynomials, values at X

Mathematica

Select[Range[1000], PrimeQ[Cyclotomic[#, 3]] &]

Prog

(PARI) for( i=1, 999, ispseudoprime( polcyclo(i, 3)) &&& print1( i", ")) /* use ...subst(polcyclo(i), x, 3)... in PARI < 2.4.2 */

Crossrefs

Cf. A019321, A072226, A138920-A138940.

Sequence in context: A190189 A129414 A157319 * A288938 A282140 A071530

Adjacent sequences: A138930 A138931 A138932 * A138934 A138935 A138936

Keyword

nonn

Author

M. F. Hasler, Apr 03 2008

Status

approved