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A138927
Indices k such that A020502(k)=Phi[k](-3) is prime, where Phi is a cyclotomic polynomial.
2
3, 5, 6, 7, 12, 13, 14, 18, 23, 24, 26, 30, 35, 36, 40, 42, 43, 60, 65, 66, 72, 77, 108, 126, 132, 142, 206, 215, 236, 276, 281, 286, 290, 304, 322, 359, 364, 391, 464, 487, 510, 522, 528, 529, 535, 558, 574, 577, 672, 680, 713, 731, 760, 799, 828, 892, 984
OFFSET
1,1
MATHEMATICA
Select[ Range[3, 1000], PrimeQ[ Cyclotomic[#, -3]] &] (* Robert G. Wilson v, Mar 25 2012 *)
PROG
(PARI) for( i=1, 999, ispseudoprime( polcyclo(i, -3)) && print1( i", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Apr 03 2008
STATUS
approved