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A082640
Triangle T(m,n) read by rows: unimodular triangulations of the grid P(m,n), m,n > 0, n <= m.
12
2, 6, 64, 20, 852, 46456, 70, 12170, 2822648, 736983568, 252, 182132, 182881520, 208902766788, 260420548144996, 924, 2801708, 12244184472, 61756221742966, 341816489625522032, 1999206934751133055518
OFFSET
1,1
COMMENTS
The limit of T(2,n)^(1/n) is (611+sqrt(73))/36. - Stepan Orevkov, Jan 31 2022
LINKS
Stepan Orevkov, Table of n, a(n) for n = 1..45 (rows 1..9)
V. Kaibel and G. M. Ziegler, Counting Lattice Triangulations, arXiv:math/0211268 [math.CO], 2002.
S. Yu. Orevkov, Counting lattice triangulations: Fredholm equations in combinatorics, arXiv:2201.12827 [math.CO], 2022.
Igor Pak, Complexity problems in enumerative combinatorics, arXiv:1803.06636 [math.CO], 2018.
EXAMPLE
Triangle begins:
2;
6, 64;
20, 852, 46456;
70, 12170, 2822648, 736983568;
...
CROSSREFS
First column is T(m, 1) = A000984(m).
Second column is T(m,2) = A296165(m).
Row sums: A151686. - N. J. A. Sloane, Jun 02 2009
Sequence in context: A134706 A145756 A030170 * A139695 A347949 A241590
KEYWORD
nonn,tabl
AUTHOR
Ralf Stephan, May 15 2003
STATUS
approved