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A046887 Numbers n such that the cyclotomic polynomial of order n has a nonzero coefficient which does not appear in any cyclotomic polynomials of lower order.

%I A046887 #11 Nov 19 2012 10:56:19
%S A046887 1,105,165,385,595,1365,1785,2145,2805,3135,6545,7917,10465,11305,
%T A046887 15015,17255,20615,25935,26565,40755,106743,171717,255255,279565,
%U A046887 285285,327845,350455,373065,463505
%N A046887 Numbers n such that the cyclotomic polynomial of order n has a nonzero coefficient which does not appear in any cyclotomic polynomials of lower order.
%e A046887 The cyclotomic polynomial cycl(105) is the first one to contain a nonzero coefficient which is not 1 or -1: it contains -2. Then for j=165 the coefficient 2 appears, etc.
%p A046887 with(numtheory): me := {}: for j from 1 to 10000 do h := {coeffs(cyclotomic(j,x))}: if me union h <> me then print(j,h minus me); me := me union h; fi; od:
%t A046887 coes = {}; Reap[For[j = 1, j <= 10000, j++, h = Select[ CoefficientList[ Cyclotomic[j, x], x], # != 0 &]; u = Union[coes, h]; If[u != coes, Print[j]; Sow[j]; coes = u]]][[2, 1]] (* _Jean-François Alcover_, Nov 19 2012, after Maple *)
%Y A046887 Cf. A013594.
%K A046887 nonn,nice
%O A046887 1,2
%A A046887 Christoph Lamm (lamm(AT)math.uni-bonn.de)
%E A046887 a(13)-a(19) from _Giovanni Resta_, Feb 01 2006
%E A046887 Added 10 terms - _T. D. Noe_, Dec 10 2008