✦ LIBER ✦

A proof of Julian West's conjecture that the number of two-stacksortable permutations of length n is 2(3n)!/((n + 1)!(2n + 1)!)

✍ Scribed by Doron Zeilberger

Publisher: Elsevier Science
Year: 1992
Tongue: English
Weight: 552 KB
Volume: 102
Category: Article
ISSN: 0012-365X
DOI: 10.1016/0012-365x(92)90351-f

No coin nor oath required. For personal study only.

✦ Synopsis

Zeilberger, D., A proof of Julian West's conjecture that the number of two-stack-sortable permutations of length n is 2(3n)!/((n + 1)!(2n + l)!), Discrete Mathematics 102 (1992) 85-93.

The Polya-Schutzenberger-Tutte methodology of weight enumeration, combined with about 10 hours of CPU time (of Maple running on Drexel University's Sun network) established Julian West's conjecture that 2-stack-sortable permutations are enumerated by sequence #651 in the Sloane listing.

📜 SIMILAR VOLUMES

Ag3.5Bi7.5S13, a New Member (N = 8) of t

Ag3.5Bi7.5S13, a New Member (N = 8) of the Homologous Series [Bi2S3]2× [AgBiS2](N—1)/2.

✍ Pierre F. Poudeu Poudeu; Michael Ruck 📂 Article 📅 2005 🏛 John Wiley and Sons ⚖ 9 KB 👁 1 views

ChemInform Abstract: Mixed Cations and S

ChemInform Abstract: Mixed Cations and Structural Complexity in (Eu1-xCax)4In3Ge4 and (Eu1-xCax)3In2Ge3 — The First Two Members of the Homologous Series A2[n+m]In2n+mGe2[n+m] (n, m = 1, 2,···∞; A: Ca, Sr, Ba, Eu, or Yb).

✍ Tae-Soo You; Paul H. Tobash; Svilen Bobev 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 21 KB 👁 1 views

## Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable v

(1S,2S,3R,6R)-6-Aminocyclohex-4-ene-1,2,

(1S,2S,3R,6R)-6-Aminocyclohex-4-ene-1,2,3-triol (= (−)-Conduramine B-1) Is a Selective Inhibitor of α-Mannosidases. Its Inhibitory Activity Is Enhanced by N-Benzylation

✍ Robert Łysek; Catherine Schütz; Pierre Vogel 📂 Article 📅 2005 🏛 John Wiley and Sons 🌐 German ⚖ 341 KB

## Abstract (−)‐ and (+)‐Conduramine B‐1 ((−)‐ and (+)‐5, resp.) have been derived from (+)‐ and (−)‐7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐one (‘naked sugars’ of the first generation). Although (−)‐5 imitates the structure of __β__‐glucosides, it does not inhibit __β__‐glucosidases but inhibits __α__‐mann

ChemInform Abstract: N-Chlorosuccinimide

ChemInform Abstract: N-Chlorosuccinimide is a Convenient Oxidant for the Synthesis of 2,4-Disubstituted 1,2,4-Thiadiazolidine-3,5-diones.

✍ Shama Nasim; Peter A. Crooks 📂 Article 📅 2009 🏛 John Wiley and Sons ⚖ 26 KB 👁 2 views

The First Structure of a Lithiated Cyana

The First Structure of a Lithiated Cyanamide; Synthesis of (PhNCNLi · HMPA)n by Extrusion of N2 and S from 5-Phenylamino-1,2,3,4-thiatriazole with Li Reagents and HMPA

✍ Dr. David R. Armstrong; F. Adele Banbury; Ian Cragg-Hine; Matthew G. Davidson; D 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 348 KB 👁 3 views

In principle, there are least four conformations in which the linker arm can join the uppermost melamine ring in 4 to the central benzene "hub' 121. Additionally. adjacent melamine rings in each arm of the Hub(MMM), unit can lie in eclipsed or staggered conformations, resulting in a total of at l e

ChemInform Abstract: The Practical Synth

ChemInform Abstract: The Practical Synthesis of a Uterine Relaxant, Bis(2-{[(2S)-2-({(2R)-2-hydroxy-2- [4-hydroxy-3-(2-hydroxyethyl)phenyl] ethyl}amino)-1,2,3,4-tetrahydronaphthalen-7-yl] oxy}-N,N-dimethylacetamide) Sulfate (KUR-1246).

✍ Takashi Yanagi; Ken Kikuchi; Hideki Takeuchi; Takehiro Ishikawa; Toshihiro Nishi 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 36 KB 👁 1 views