A089010 - OEIS

A089010

a(n) = 1 if n is an exponent of the Weyl group W(E_8), 0 otherwise.

1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

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OFFSET

1,1

COMMENTS

The exponents are 1, 7, 11, 13, 17, 19, 23, 29. The point of this sequence is that a similar generating function gives the exponents for any finite Coxeter group.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for characteristic functions

FORMULA

G.f.: x*(1-x^20)*(1-x^24)/((1-x^6)*(1-x^10)).

MATHEMATICA

PadRight[CoefficientList[Series[x(1-x^20)(1-x^24)/((1-x^6)(1-x^10)), {x, 0, 120}], x], 120, 0] (* Harvey P. Dale, May 15 2018 *)

PROG

(PARI) Vec(x*(1-x^20)*(1-x^24)/((1-x^6)*(1-x^10)) + O(x^90)) \\ Michel Marcus, Aug 19 2015

CROSSREFS

Cf. A005776, A089011.

Sequence in context: A079979 A288711 A347312 * A162289 A373139 A122276

Adjacent sequences: A089007 A089008 A089009 * A089011 A089012 A089013

KEYWORD

easy,nonn

AUTHOR

Paul Boddington, Nov 03 2003

STATUS

approved