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On trees and noncrossing partitions

โœ Scribed by Martin Klazar


Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
426 KB
Volume
82
Category
Article
ISSN
0166-218X

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โœฆ Synopsis


We give a simple and natural proof of (an extension of) the identity P(X. 1. )I ) = t-'2( X I. I -I. II --I ). The number P(li, I, 17) counts noncrossing partitions of { I, 2.

I} unto II parts such that no part contains two numbers .Y and J'. O<.v --.v<k. The lower index 2 indicate\ partitions with no part of size three or more. We USC the identity to give quick proofs of the closed t'ormulac for P(k. I, n) when k is I. 2. or 3.


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