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A250189 Numbers n such that Phi(40,n) is prime, where Phi is the cyclotomic polynomial. 2
2, 3, 4, 31, 37, 39, 46, 77, 98, 119, 124, 143, 144, 154, 169, 197, 205, 232, 245, 266, 291, 295, 297, 305, 308, 319, 332, 333, 413, 426, 431, 437, 454, 459, 472, 483, 513, 528, 531, 542, 579, 617, 619, 635, 647, 677, 724, 737, 748, 780, 806, 815, 819, 820, 840, 851, 858, 870, 875, 907, 920, 927, 940, 983, 1002, 1028 (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[1200], PrimeQ[Cyclotomic[40, #]] &] (* Vincenzo Librandi, Jan 16 2015 *)

PROG

(PARI) {is(n)=isprime(polcyclo(40, n))};

for(n=1, 1000, if(is(n), print1(n, ", "))) \\ G. C. Greubel, May 20 2018

CROSSREFS

Cf. A246392.

Sequence in context: A305205 A064889 A057917 * A255253 A076592 A004844

Adjacent sequences:  A250186 A250187 A250188 * A250190 A250191 A250192

KEYWORD

nonn

AUTHOR

R. J. Mathar, Jan 12 2015

STATUS

approved

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Last modified September 26 12:04 EDT 2021. Contains 347665 sequences. (Running on oeis4.)