OFFSET
1,2
LINKS
Peter Luschny, Table of n, a(n) for n = 1..100. Data from George Spahn and Doron Zeilberger, see link.
George Spahn and Doron Zeilberger, Automatic Counting of Generalized Latin Rectangles and Trapezoids, Enumerative Combinatorics and Applications, 2:1 (2022).
George Spahn and Doron Zeilberger, Latin trapezoids with three rows, the first 100 terms.
George Spahn and Doron Zeilberger, Latin trapezoids, a Maple package.
EXAMPLE
There are 6 reduced Latin trapezoids of height 3 with base of length 4:
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2, 3; | 4, 3; | 2, 3;
3, 1, 2; | 3, 1, 2; | 3, 4, 1;
1, 2, 3, 4; | 1, 2, 3, 4; | 1, 2, 3, 4;
-----------------------------------------------
2, 1; | 2, 3; | 2, 3;
3, 4, 2; | 3, 4, 2; | 4, 1, 2;
1, 2, 3, 4; | 1, 2, 3, 4; | 1, 2, 3, 4;
-----------------------------------------------
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Oct 22 2021
STATUS
approved