

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.


5



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
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..29.


EXAMPLE

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.


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]] (* JeanFrançois Alcover, Nov 19 2012, after Maple *)


CROSSREFS

Cf. A013594.
Sequence in context: A234103 A128284 A161962 * A026066 A167629 A326141
Adjacent sequences: A046884 A046885 A046886 * A046888 A046889 A046890


KEYWORD

nonn,nice


AUTHOR

Christoph Lamm (lamm(AT)math.unibonn.de)


EXTENSIONS

a(13)a(19) from Giovanni Resta, Feb 01 2006
Added 10 terms  T. D. Noe, Dec 10 2008


STATUS

approved



