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A160497
Values of pq such that there are only two residue classes (mod pq) of primes r that produce flat cyclotomic polynomial Phi(pqr,x).
2
15, 35, 65, 77, 85, 91, 95, 115, 119, 133, 143, 161, 185, 187, 209, 215, 217, 221, 235, 247, 259, 265, 287, 299, 319, 323, 329, 335, 341, 365, 371, 377, 391, 403, 407, 413, 415, 427, 437, 451, 469, 473, 481, 485, 493, 511, 515, 517, 527
OFFSET
1,1
COMMENTS
Except for 91, 95, 287, and 473, it appears that for prime p>3, pq is here only if q-1 and q+1 are not multiples of p.
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, May 15 2009
STATUS
approved