A089012 a(n) = 1 if n is an exponent of the Weyl group W(E_6), 0 otherwise.

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

Offset

1,1

Comments

The exponents are 1, 4, 5, 7, 8, 11. 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..1001

Index entries for characteristic functions

Formula

G.f.: (1-x^8)*(1-x^9)/((1-x^3)*(1-x^4)).

Mathematica

CoefficientList[Series[(1 - x^8) (1 - x^9)/((1 - x^3) (1 - x^4)), {x, 0, 11}], x] (* Michael De Vlieger, Oct 10 2017 *)

Prog

(Scheme) (define (A089012 n) (if (member n '(1 4 5 7 8 11)) 1 0)) ;; Antti Karttunen, Oct 10 2017

Crossrefs

Characteristic function of A005556.

Sequence in context: A078650 A285305 A028863 * A083035 A359422 A356161

Adjacent sequences: A089009 A089010 A089011 * A089013 A089014 A089015

Keyword

easy,nonn

Author

Paul Boddington, Nov 03 2003

Extensions

More zeros from Antti Karttunen, Oct 10 2017

Status

approved