A160497 - OEIS

%I #2 Mar 30 2012 17:22:54

%S 15,35,65,77,85,91,95,115,119,133,143,161,185,187,209,215,217,221,235,

%T 247,259,265,287,299,319,323,329,335,341,365,371,377,391,403,407,413,

%U 415,427,437,451,469,473,481,485,493,511,515,517,527

%N Values of pq such that there are only two residue classes (mod pq) of primes r that produce flat cyclotomic polynomial Phi(pqr,x).

%C 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.

%Y A160496

%K nonn

%O 1,1

%A _T. D. Noe_, May 15 2009