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Statistic identifier: St001145

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Collection: Finite Cartan types

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Description: The largest coefficient in a Kazhdan Lusztig polynomial of the Weyl group of given type.

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References: 

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Code:
def statistic(C):
    W = CoxeterGroup(C, implementation='coxeter3')
    r = set([])
    for u in W:
        U = (W(v) for v in W.bruhat_interval(u, W.long_element()))
        next(U)
        for v in U:
            p = W.kazhdan_lusztig_polynomial(u, v)
            c = set(p.coefficients())
            r = r.union(c)
    return max(r)


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Statistic values:

['A',1] => 1
['A',2] => 1
['B',2] => 1
['G',2] => 1
['A',3] => 1
['B',3] => 1
['C',3] => 1
['A',4] => 2
['B',4] => 5
['C',4] => 5
['D',4] => 4
['F',4] => 12
['A',5] => 4

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Created: Apr 19, 2018 at 00:00 by Martin Rubey

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Last Updated: Apr 19, 2018 at 09:07 by Martin Rubey