MOSEL: A Sound and Efficient Tool for M2L(Str)

Permutation tableaux were introduced by Steingrmsson and Williams. Corteel and Kim defined the sign of a permutation tableau in terms of the number of unrestricted columns. The sign-imbalance of permutation tableaux of length n is the sum of signs over ...

• Provide a bijection combinatorial proof for the facts that The number of derangements of length n equals the number of permutations of length n that have ...

A derangement is a permutation in which no entry is at its original position. The number of derangements of [ n ] is called the “derangement number” or “de Montmort number”, and is denoted by D n. The sequence { D n } enumerates, in ...

We describe the recursive structures of the set of two-stack sortable permutations which avoid 132 and the set of two-stack sortable permutations which contain 132 exactly once. Using these results and standard generating function techniques, we ...