Identifier
Identifier
Values
['A',1] generating graphics... => 3
['A',2] generating graphics... => 12
['B',2] generating graphics... => 15
['G',2] generating graphics... => 21
['A',3] generating graphics... => 55
['B',3] generating graphics... => 84
['C',3] generating graphics... => 84
['A',4] generating graphics... => 273
['B',4] generating graphics... => 495
['C',4] generating graphics... => 495
['D',4] generating graphics... => 336
['F',4] generating graphics... => 780
['A',5] generating graphics... => 1428
['B',5] generating graphics... => 3003
['C',5] generating graphics... => 3003
['D',5] generating graphics... => 2079
['A',6] generating graphics... => 7752
['B',6] generating graphics... => 18564
['C',6] generating graphics... => 18564
['D',6] generating graphics... => 13013
['E',6] generating graphics... => 16588
['A',7] generating graphics... => 43263
['B',7] generating graphics... => 116280
['C',7] generating graphics... => 116280
['D',7] generating graphics... => 82212
['E',7] generating graphics... => 144210
['A',8] generating graphics... => 246675
['B',8] generating graphics... => 735471
['C',8] generating graphics... => 735471
['D',8] generating graphics... => 523260
['E',8] generating graphics... => 1520922
click to show generating function       
Description
The second Fuss-Catalan number of a finite Cartan type.
The Fuss-Catalan numbers of a finite Cartan type are given by
$$\frac{1}{|W|}\prod (d_i+mh) = \prod \frac{d_i+mh}{d_i}$$
where the products run over all degrees of homoneneous fundamenal invariants of the Weyl group of a Cartan type.
Code
def statistic(cartan_type):
    W = ReflectionGroup(cartan_type)
    return W.fuss_catalan_number(m=2)

Created
Jun 25, 2017 at 10:10 by Christian Stump
Updated
Nov 21, 2017 at 09:31 by Christian Stump