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.

1, 105, 165, 385, 595, 1365, 1785, 2145, 2805, 3135, 6545, 7917, 10465, 11305, 15015, 17255, 20615, 25935, 26565, 40755, 106743, 171717, 255255, 279565, 285285, 327845, 350455, 373065, 463505

Offset: 1

Author

Christoph Lamm (lamm(AT)math.uni-bonn.de)

Keywords

• nonn
• nice

Examples

			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.
		

Crossrefs

Cf. A013594.

Programs

Maple

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:

Mathematica

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 *)

Extensions

a(13)-a(19) from Giovanni Resta, Feb 01 2006

Added 10 terms - T. D. Noe, Dec 10 2008