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A250190 Numbers n such that Phi(42,n) is prime, where Phi is the cyclotomic polynomial. 2
2, 6, 8, 11, 23, 35, 41, 49, 58, 65, 85, 88, 97, 107, 111, 139, 144, 161, 170, 197, 214, 217, 223, 230, 238, 247, 274, 298, 301, 323, 382, 389, 393, 398, 403, 427, 445, 452, 473, 480, 497, 511, 561, 575, 595, 601, 604, 606, 615, 629, 651, 652, 680, 685, 702, 725, 762, 770, 774, 781, 805, 814, 912, 918, 942, 987, 1030 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

Select[Range[1100], PrimeQ[Cyclotomic[42, #]] &] (* Vincenzo Librandi, Jan 16 2015 *)

PROG

(PARI) {is(n)=isprime(polcyclo(42, n))};

for(n=1, 1000, if(is(n)==1, print1(n, ", "))) \\ G. C. Greubel, May 18 2018

CROSSREFS

Cf. A246392.

Sequence in context: A076991 A130205 A054067 * A244342 A064212 A056906

Adjacent sequences:  A250187 A250188 A250189 * A250191 A250192 A250193

KEYWORD

nonn

AUTHOR

R. J. Mathar, Jan 12 2015

STATUS

approved

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Last modified September 16 08:14 EDT 2021. Contains 347469 sequences. (Running on oeis4.)