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A001217

Sorted list of orders of Weyl groups of types A_n, B_n, D_n, E_n, F_4, G_2.

2

1, 2, 4, 6, 8, 12, 24, 48, 120, 192, 384, 720, 1152, 1920, 3840, 5040, 23040, 40320, 46080, 51840, 322560, 362880, 645120, 2903040, 3628800, 5160960, 10321920, 39916800, 92897280, 185794560, 479001600, 696729600, 1857945600, 3715891200

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..34.

N. Bourbaki, Groupes et algèbres de Lie, Chap. 4, 5, 6.

FORMULA

O(A_n) = (n+1)! = A000142(n+1), O(B_n) = O(C_n) = 2^n*n! = A000165(n), O(D_n) = 2^(n-1)*n! = A002866(n), O(E_n) = A003134(n), O(F_4) = 1152, O(G_2) = 12. Hence, {A001217} = {A000142} union {A000165} union {A002866} union {A003134} union {12, 1152}. - Sean A. Irvine, Jul 11 2019

CROSSREFS

Sequence in context: A307187 A374781 A340014 * A131885 A173941 A194406

Adjacent sequences: A001214 A001215 A001216 * A001218 A001219 A001220

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane

STATUS

approved