dmtcs:2492 -
Discrete Mathematics & Theoretical Computer Science,
January 1, 2015,
DMTCS Proceedings, 27th International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2015)
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https://doi.org/10.46298/dmtcs.2492
Four Variations on Graded PosetsConference paper
Authors: Yan X Zhang 1
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Yan X Zhang
1 Department of Mathematics [Berkeley]
We explore the enumeration of some natural classes of graded posets, including (2+2)-avoiding graded posets, (3+1)-avoiding graded posets, (2+2)- and (3+1)-avoiding graded posets, and the set of all graded posets. As part of this story, we discuss a situation when we can switch between enumeration of labeled and unlabeled objects with ease, which helps us generalize a result by Postnikov and Stanley from the theory of hyperplane arrangements, answer a question posed by Stanley, and see an old result of Klarner in a new light.