Combinatorics on permutation tableaux of type and type
arXiv:1006.3812
Abstract
We give another bijective proof of a result of Corteel and Nadeau. We find a generating function related to unrestricted columns of permutation tableaux. As a consequence, we obtain a sign-imbalance formula for permutation tableaux. We extend the first bijection of Corteel and Nadeau between permutations and permutation tableaux to type objects. Using this type bijection, we generalize a result of Lam and Williams. We prove that the bijection of Corteel and Nadeau and our type bijection can be expressed as zigzag maps on the alternative representation.
20 pages, 9 figures, final version