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A138939 Indices k such that A019327(k)=Phi[k](9) is prime, where Phi is a cyclotomic polynomial. 3
6, 12, 18, 20, 30, 36, 54, 66, 118, 138, 152, 182, 232, 264, 336, 340, 380, 414, 446, 492, 540, 624, 720, 762, 1066, 1094, 1098, 1170, 1230, 1254, 1320, 1428, 1546, 2018, 2574, 2724, 2804, 2920, 3074, 3316, 3646, 4124, 4132, 4186, 4620, 4802 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Price, Table of n, a(n) for n = 1..64

Yves Gallot, Cyclotomic polynomials and prime numbers

Index entries for cyclotomic polynomials, values at X

MATHEMATICA

Select[Range[1000], PrimeQ[Cyclotomic[#, 9]] &]

PROG

(PARI) for( i=1, 999, ispseudoprime( polcyclo(i, 9)) && print1( i", ")) /* use ...subst( polcyclo(i), x, 9)... in PARI < 2.4.2 */

CROSSREFS

Cf. A019327, A138920-A138940.

Sequence in context: A228870 A291022 A316221 * A221220 A046411 A315723

Adjacent sequences:  A138936 A138937 A138938 * A138940 A138941 A138942

KEYWORD

nonn

AUTHOR

M. F. Hasler, Apr 03 2008

EXTENSIONS

a(25)-a(46) from Robert Price, Apr 28 2012

STATUS

approved

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Last modified April 6 11:51 EDT 2020. Contains 333273 sequences. (Running on oeis4.)