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%I #20 Feb 23 2024 07:27:51
%S 14,15,28,30,45,56,60,75,90,98,112,120,135,150,180,196,224,225,240,
%T 270,300,360,375,392,405,448,450,480,540,600,675,686,720,750,784,810,
%U 896,900,960,1080,1125,1200,1215,1350,1372,1440,1500,1568,1620,1792,1800,1875
%N Numbers k such that k-th cyclotomic polynomial has exactly 3 negative coefficients.
%H Vincenzo Librandi, <a href="/A085900/b085900.txt">Table of n, a(n) for n = 0..96</a>
%t Select[Range@ 2000, Count[CoefficientList[Cyclotomic[#, x], x], _?(# < 0 &)] == 3 &] (* _Michael De Vlieger_, Oct 26 2017 *)
%Y Cf. A085459, A086780.
%K nonn
%O 0,1
%A Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 16 2003
%E More terms from _Paolo P. Lava_, Oct 26 2017