***************************************************************************** * www.FindStat.org - The Combinatorial Statistic Finder * * * * Copyright (C) 2019 The FindStatCrew * * * * This information is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * ***************************************************************************** ----------------------------------------------------------------------------- Statistic identifier: St000851 ----------------------------------------------------------------------------- Collection: Finite Cartan types ----------------------------------------------------------------------------- Description: The third 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. ----------------------------------------------------------------------------- References: ----------------------------------------------------------------------------- Code: def statistic(cartan_type): W = ReflectionGroup(cartan_type) return W.fuss_catalan_number(3) ----------------------------------------------------------------------------- Statistic values: ['A',1] => 4 ['A',2] => 22 ['B',2] => 28 ['G',2] => 40 ['A',3] => 140 ['B',3] => 220 ['C',3] => 220 ['A',4] => 969 ['B',4] => 1820 ['C',4] => 1820 ['D',4] => 1210 ['F',4] => 2926 ['A',5] => 7084 ['B',5] => 15504 ['C',5] => 15504 ['D',5] => 10556 ['A',6] => 53820 ['B',6] => 134596 ['C',6] => 134596 ['D',6] => 93024 ['E',6] => 119966 ['A',7] => 420732 ['B',7] => 1184040 ['C',7] => 1184040 ['D',7] => 826804 ['E',7] => 1484032 ['A',8] => 3362260 ['B',8] => 10518300 ['C',8] => 10518300 ['D',8] => 7400250 ['E',8] => 22309287 ----------------------------------------------------------------------------- Created: Jun 25, 2017 at 10:11 by Christian Stump ----------------------------------------------------------------------------- Last Updated: Jun 25, 2017 at 10:11 by Christian Stump