***************************************************************************** * 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: St000478 ----------------------------------------------------------------------------- Collection: Integer partitions ----------------------------------------------------------------------------- Description: Another weight of a partition according to Alladi. According to Theorem 3.4 (Alladi 2012) in [1] $$ \sum_{\pi\in GG_1(r)} w_1(\pi) $$ equals the number of partitions of $r$ whose odd parts are all distinct. $GG_1(r)$ is the set of partitions of $r$ where consecutive entries differ by at least $2$, and consecutive even entries differ by at least $4$. ----------------------------------------------------------------------------- References: [1] Berkovich, A., Kemal Uncu, A. Variation on a theme of Nathan Fine. New weighted partition identities [[arXiv:1605.00291]] ----------------------------------------------------------------------------- Code: def statistic(pi): """ sage: statistic(Partition([18,12,7,5])) 12 Theorem (3.12) of http://arxiv.org/pdf/1605.00291.pdf: sage: r=10; DO = [1 for pi in Partitions(r) if len(set(p for p in pi if is_odd(p))) == len([p for p in pi if is_odd(p)])] sage: GG1 = [pi for pi in Partitions(r, max_slope=-2) if all(pi[j]-pi[j+1] != 2 for j in range(len(pi)-1) if is_even(pi[j]))] sage: sum(statistic(pi) for pi in GG1) == len(DO) True """ def delta_even(p): if is_even(p): return 1 else: return 0 return (pi[-1] + 1 - delta_even(pi[-1]))/2 * prod((pi[i] - pi[i+1] - delta_even(pi[i]) - delta_even(pi[i+1]))/2 for i in range(len(pi)-1)) ----------------------------------------------------------------------------- Statistic values: [2] => 1 [1,1] => 0 [3] => 2 [2,1] => 0 [1,1,1] => 0 [4] => 2 [3,1] => 1 [2,2] => -1 [2,1,1] => 0 [1,1,1,1] => 0 [5] => 3 [4,1] => 1 [3,2] => 0 [3,1,1] => 0 [2,2,1] => 0 [2,1,1,1] => 0 [1,1,1,1,1] => 0 [6] => 3 [5,1] => 2 [4,2] => 0 [4,1,1] => 0 [3,3] => 0 [3,2,1] => 0 [3,1,1,1] => 0 [2,2,2] => 1 [2,2,1,1] => 0 [2,1,1,1,1] => 0 [1,1,1,1,1,1] => 0 [7] => 4 [6,1] => 2 [5,2] => 1 [5,1,1] => 0 [4,3] => 0 [4,2,1] => 0 [4,1,1,1] => 0 [3,3,1] => 0 [3,2,2] => 0 [3,2,1,1] => 0 [3,1,1,1,1] => 0 [2,2,2,1] => 0 [2,2,1,1,1] => 0 [2,1,1,1,1,1] => 0 [1,1,1,1,1,1,1] => 0 [8] => 4 [7,1] => 3 [6,2] => 1 [6,1,1] => 0 [5,3] => 2 [5,2,1] => 0 [5,1,1,1] => 0 [4,4] => -2 [4,3,1] => 0 [4,2,2] => 0 [4,2,1,1] => 0 [4,1,1,1,1] => 0 [3,3,2] => 0 [3,3,1,1] => 0 [3,2,2,1] => 0 [3,2,1,1,1] => 0 [3,1,1,1,1,1] => 0 [2,2,2,2] => -1 [2,2,2,1,1] => 0 [2,2,1,1,1,1] => 0 [2,1,1,1,1,1,1] => 0 [1,1,1,1,1,1,1,1] => 0 [9] => 5 [8,1] => 3 [7,2] => 2 [7,1,1] => 0 [6,3] => 2 [6,2,1] => 0 [6,1,1,1] => 0 [5,4] => 0 [5,3,1] => 1 [5,2,2] => -1 [5,2,1,1] => 0 [5,1,1,1,1] => 0 [4,4,1] => -1 [4,3,2] => 0 [4,3,1,1] => 0 [4,2,2,1] => 0 [4,2,1,1,1] => 0 [4,1,1,1,1,1] => 0 [3,3,3] => 0 [3,3,2,1] => 0 [3,3,1,1,1] => 0 [3,2,2,2] => 0 [3,2,2,1,1] => 0 [3,2,1,1,1,1] => 0 [3,1,1,1,1,1,1] => 0 [2,2,2,2,1] => 0 [2,2,2,1,1,1] => 0 [2,2,1,1,1,1,1] => 0 [2,1,1,1,1,1,1,1] => 0 [1,1,1,1,1,1,1,1,1] => 0 [10] => 5 [9,1] => 4 [8,2] => 2 [8,1,1] => 0 [7,3] => 4 [7,2,1] => 0 [7,1,1,1] => 0 [6,4] => 0 [6,3,1] => 1 [6,2,2] => -1 [6,2,1,1] => 0 [6,1,1,1,1] => 0 [5,5] => 0 [5,4,1] => 0 [5,3,2] => 0 [5,3,1,1] => 0 [5,2,2,1] => 0 [5,2,1,1,1] => 0 [5,1,1,1,1,1] => 0 [4,4,2] => 0 [4,4,1,1] => 0 [4,3,3] => 0 [4,3,2,1] => 0 [4,3,1,1,1] => 0 [4,2,2,2] => 0 [4,2,2,1,1] => 0 [4,2,1,1,1,1] => 0 [4,1,1,1,1,1,1] => 0 [3,3,3,1] => 0 [3,3,2,2] => 0 [3,3,2,1,1] => 0 [3,3,1,1,1,1] => 0 [3,2,2,2,1] => 0 [3,2,2,1,1,1] => 0 [3,2,1,1,1,1,1] => 0 [3,1,1,1,1,1,1,1] => 0 [2,2,2,2,2] => 1 [2,2,2,2,1,1] => 0 [2,2,2,1,1,1,1] => 0 [2,2,1,1,1,1,1,1] => 0 [2,1,1,1,1,1,1,1,1] => 0 [1,1,1,1,1,1,1,1,1,1] => 0 [11] => 6 [10,1] => 4 [9,2] => 3 [9,1,1] => 0 [8,3] => 4 [8,2,1] => 0 [8,1,1,1] => 0 [7,4] => 2 [7,3,1] => 2 [7,2,2] => -2 [7,2,1,1] => 0 [7,1,1,1,1] => 0 [6,5] => 0 [6,4,1] => 0 [6,3,2] => 0 [6,3,1,1] => 0 [6,2,2,1] => 0 [6,2,1,1,1] => 0 [6,1,1,1,1,1] => 0 [5,5,1] => 0 [5,4,2] => 0 [5,4,1,1] => 0 [5,3,3] => 0 [5,3,2,1] => 0 [5,3,1,1,1] => 0 [5,2,2,2] => 1 [5,2,2,1,1] => 0 [5,2,1,1,1,1] => 0 [5,1,1,1,1,1,1] => 0 [4,4,3] => 0 [4,4,2,1] => 0 [4,4,1,1,1] => 0 [4,3,3,1] => 0 [4,3,2,2] => 0 [4,3,2,1,1] => 0 [4,3,1,1,1,1] => 0 [4,2,2,2,1] => 0 [4,2,2,1,1,1] => 0 [4,2,1,1,1,1,1] => 0 [4,1,1,1,1,1,1,1] => 0 [3,3,3,2] => 0 [3,3,3,1,1] => 0 [3,3,2,2,1] => 0 [3,3,2,1,1,1] => 0 [3,3,1,1,1,1,1] => 0 [3,2,2,2,2] => 0 [3,2,2,2,1,1] => 0 [3,2,2,1,1,1,1] => 0 [3,2,1,1,1,1,1,1] => 0 [3,1,1,1,1,1,1,1,1] => 0 [2,2,2,2,2,1] => 0 [2,2,2,2,1,1,1] => 0 [2,2,2,1,1,1,1,1] => 0 [2,2,1,1,1,1,1,1,1] => 0 [2,1,1,1,1,1,1,1,1,1] => 0 [1,1,1,1,1,1,1,1,1,1,1] => 0 [12] => 6 [11,1] => 5 [10,2] => 3 [10,1,1] => 0 [9,3] => 6 [9,2,1] => 0 [9,1,1,1] => 0 [8,4] => 2 [8,3,1] => 2 [8,2,2] => -2 [8,2,1,1] => 0 [8,1,1,1,1] => 0 [7,5] => 3 [7,4,1] => 1 [7,3,2] => 0 [7,3,1,1] => 0 [7,2,2,1] => 0 [7,2,1,1,1] => 0 [7,1,1,1,1,1] => 0 [6,6] => -3 [6,5,1] => 0 [6,4,2] => 0 [6,4,1,1] => 0 [6,3,3] => 0 [6,3,2,1] => 0 [6,3,1,1,1] => 0 [6,2,2,2] => 1 [6,2,2,1,1] => 0 [6,2,1,1,1,1] => 0 [6,1,1,1,1,1,1] => 0 [5,5,2] => 0 [5,5,1,1] => 0 [5,4,3] => 0 [5,4,2,1] => 0 [5,4,1,1,1] => 0 [5,3,3,1] => 0 [5,3,2,2] => 0 [5,3,2,1,1] => 0 [5,3,1,1,1,1] => 0 [5,2,2,2,1] => 0 [5,2,2,1,1,1] => 0 [5,2,1,1,1,1,1] => 0 [5,1,1,1,1,1,1,1] => 0 [4,4,4] => 2 [4,4,3,1] => 0 [4,4,2,2] => 0 [4,4,2,1,1] => 0 [4,4,1,1,1,1] => 0 [4,3,3,2] => 0 [4,3,3,1,1] => 0 [4,3,2,2,1] => 0 [4,3,2,1,1,1] => 0 [4,3,1,1,1,1,1] => 0 [4,2,2,2,2] => 0 [4,2,2,2,1,1] => 0 [4,2,2,1,1,1,1] => 0 [4,2,1,1,1,1,1,1] => 0 [4,1,1,1,1,1,1,1,1] => 0 [3,3,3,3] => 0 [3,3,3,2,1] => 0 [3,3,3,1,1,1] => 0 [3,3,2,2,2] => 0 [3,3,2,2,1,1] => 0 [3,3,2,1,1,1,1] => 0 [3,3,1,1,1,1,1,1] => 0 [3,2,2,2,2,1] => 0 [3,2,2,2,1,1,1] => 0 [3,2,2,1,1,1,1,1] => 0 [3,2,1,1,1,1,1,1,1] => 0 [3,1,1,1,1,1,1,1,1,1] => 0 [2,2,2,2,2,2] => -1 [2,2,2,2,2,1,1] => 0 [2,2,2,2,1,1,1,1] => 0 [2,2,2,1,1,1,1,1,1] => 0 [2,2,1,1,1,1,1,1,1,1] => 0 [2,1,1,1,1,1,1,1,1,1,1] => 0 [1,1,1,1,1,1,1,1,1,1,1,1] => 0 ----------------------------------------------------------------------------- Created: May 03, 2016 at 12:34 by Martin Rubey ----------------------------------------------------------------------------- Last Updated: May 03, 2016 at 15:48 by Martin Rubey