***************************************************************************** * 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: St001364 ----------------------------------------------------------------------------- Collection: Integer partitions ----------------------------------------------------------------------------- Description: The number of permutations whose cube equals a fixed permutation of given cycle type. For example, the permutation $\pi=412365$ has cycle type $(4,2)$ and $234165$ is the unique permutation whose cube is $\pi$. ----------------------------------------------------------------------------- References: ----------------------------------------------------------------------------- Code: @cached_function def statistic_dict(n, k): d = {} for pi in Permutations(n): sigma = pi^k d[sigma] = d.get(sigma, 0) + 1 return d def statistic(la): n = la.size() d = statistic_dict(n, 3) sigma = standard_permutation(la) return d.get(sigma, 0) ----------------------------------------------------------------------------- Statistic values: [1] => 1 [2] => 1 [1,1] => 1 [3] => 0 [2,1] => 1 [1,1,1] => 3 [4] => 1 [3,1] => 0 [2,2] => 1 [2,1,1] => 1 [1,1,1,1] => 9 [5] => 1 [4,1] => 1 [3,2] => 0 [3,1,1] => 0 [2,2,1] => 1 [2,1,1,1] => 3 [1,1,1,1,1] => 21 [6] => 0 [5,1] => 1 [4,2] => 1 [4,1,1] => 1 [3,3] => 0 [3,2,1] => 0 [3,1,1,1] => 0 [2,2,2] => 9 [2,2,1,1] => 1 [2,1,1,1,1] => 9 [1,1,1,1,1,1] => 81 [7] => 1 [6,1] => 0 [5,2] => 1 [5,1,1] => 1 [4,3] => 0 [4,2,1] => 1 [4,1,1,1] => 3 [3,3,1] => 0 [3,2,2] => 0 [3,2,1,1] => 0 [3,1,1,1,1] => 0 [2,2,2,1] => 9 [2,2,1,1,1] => 3 [2,1,1,1,1,1] => 21 [1,1,1,1,1,1,1] => 351 [8] => 1 [7,1] => 1 [6,2] => 0 [6,1,1] => 0 [5,3] => 0 [5,2,1] => 1 [5,1,1,1] => 3 [4,4] => 1 [4,3,1] => 0 [4,2,2] => 1 [4,2,1,1] => 1 [4,1,1,1,1] => 9 [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] => 33 [2,2,2,1,1] => 9 [2,2,1,1,1,1] => 9 [2,1,1,1,1,1,1] => 81 [1,1,1,1,1,1,1,1] => 1233 [9] => 0 [8,1] => 1 [7,2] => 1 [7,1,1] => 1 [6,3] => 0 [6,2,1] => 0 [6,1,1,1] => 0 [5,4] => 1 [5,3,1] => 0 [5,2,2] => 1 [5,2,1,1] => 1 [5,1,1,1,1] => 9 [4,4,1] => 1 [4,3,2] => 0 [4,3,1,1] => 0 [4,2,2,1] => 1 [4,2,1,1,1] => 3 [4,1,1,1,1,1] => 21 [3,3,3] => 18 [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] => 33 [2,2,2,1,1,1] => 27 [2,2,1,1,1,1,1] => 21 [2,1,1,1,1,1,1,1] => 351 [1,1,1,1,1,1,1,1,1] => 5769 ----------------------------------------------------------------------------- Created: Mar 15, 2019 at 20:50 by Martin Rubey ----------------------------------------------------------------------------- Last Updated: Mar 15, 2019 at 20:50 by Martin Rubey