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Automatic counting of generalized Latin rectangles and trapezoids. (English) Zbl 1512.05051

Summary: In this case study in “fully automated enumeration”, we illustrate how to take full advantage of symbolic computation by developing (what we call) ‘symbolic-dynamical-programming’ algorithms for computing many terms of ‘hard to compute sequences’, namely the number of Latin trapezoids, generalized derangements, and generalized three-rowed Latin rectangles. At the end, we also sketch the proof of a generalization of I. M. Gessel’s 1987 theorem [Bull. Am. Math. Soc., New Ser. 16, 79–82 (1987; Zbl 0617.05015)] that says that for any number of rows, \(k\), the number of Latin rectangles with \(k\) rows and \(n\) columns is \(P\)-recursive in \(n\). Our algorithms are fully implemented in Maple and generated quite a few terms of such sequences.

MSC:

05A19 Combinatorial identities, bijective combinatorics
33F10 Symbolic computation of special functions (Gosper and Zeilberger algorithms, etc.)

Citations:

Zbl 0617.05015

References:

[1] K. P. Bogart and J. Q. Longyear, Counting 3 by n Latin rectangles, Proc. Amer. Math. Soc. 54 (1976), 463-467. · Zbl 0295.05004
[2] I. M. Gessel, Counting three-line Latin rectangles, Lect. Notes Math. 1234 (1986), Springer, 106-111. · Zbl 0612.05015
[3] I. M. Gessel, Counting Latin rectangles, Bull. Amer. Math. Soc. (N.S.) 16 (1987), 79-82. · Zbl 0617.05015
[4] I. Kaplansky, Solution of the problème des ménages, Bull. Amer. Math. Soc. 49 (1943), 784-785. [Reprinted in pp. 122-123, “Classical Papers in Combinatorics”, edited by Ira Gessel and Gian-Carlo Rota, Birkhauser, 1987] · Zbl 0060.02904
[5] J. Riordan, ’Introduction to Combinatorial Analysis’, Dover, originally published by John Wiley, 1958. · Zbl 0078.00805
[6] D. Zeilberger, A Holonomic systems approach to special functions identities, J. of Computational and Applied Math. 32 (1990), 321-368. · Zbl 0738.33001
[7] D. Zeilberger, Automatic CounTilings, The Personal Journal pf Shalosh B. Ekhad and Doron Zeilberger https://sites.math.rutgers.edu/ zeilberg/mamarim/mamarimhtml/tilings.html.
[8] D. Zeilberger, Automatic Enumeration of Generalized Ménage Numbers, Séminaire Lotharingien de Com-binatoire 71 (2014), Article B71a. · Zbl 1297.05021
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