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A138933
Indices k such that A019321(k)=Phi[k](3) is prime, where Phi is a cyclotomic polynomial.
4
1, 3, 6, 7, 9, 10, 12, 13, 14, 15, 21, 24, 26, 33, 36, 40, 46, 60, 63, 70, 71, 72, 86, 103, 108, 130, 132, 143, 145, 154, 161, 236, 255, 261, 276, 279, 287, 304, 364, 430, 464, 513, 528, 541, 562, 665, 672, 680, 707, 718, 747, 760, 782, 828, 875, 892, 974, 984
OFFSET
1,2
MATHEMATICA
Select[Range[1000], PrimeQ[Cyclotomic[#, 3]] &]
PROG
(PARI) for( i=1, 999, ispseudoprime( polcyclo(i, 3)) && print1( i", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Apr 03 2008
STATUS
approved