login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A250178
Numbers k such that Phi_22(k) is prime, where Phi is the cyclotomic polynomial.
19
2, 6, 12, 13, 23, 24, 26, 35, 62, 69, 91, 105, 147, 160, 163, 183, 185, 193, 229, 232, 233, 236, 248, 262, 269, 280, 294, 303, 315, 330, 376, 394, 426, 430, 440, 464, 469, 491, 492, 508, 537, 625, 629, 647, 653, 666, 752, 772, 775, 786, 788, 832, 840, 852, 854, 855, 859, 905, 922, 972, 993, 998
OFFSET
1,1
COMMENTS
Numbers k such that (k^11+1)/(k+1) is a prime. - Vincenzo Librandi, May 21 2018
LINKS
MATHEMATICA
a250178[n_] := Select[Range[n], PrimeQ@Cyclotomic[22, #] &]; a250178[1000] (* Michael De Vlieger, Dec 25 2014 *)
PROG
(PARI) isok(n) = isprime(polcyclo(22, n)); \\ Michel Marcus, Sep 29 2015
(Magma) [n: n in [1..1000]| IsPrime((n^11+1) div (n+1))]; // Vincenzo Librandi, May 21 2018
CROSSREFS
See A250177 for references.
Sequence in context: A152667 A145892 A216429 * A154712 A079849 A260907
KEYWORD
nonn
AUTHOR
Eric Chen, Dec 24 2014
STATUS
approved