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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. 2
2, 6, 64, 20, 852, 46456, 70, 12170, 2822648, 736983568, 252, 182132, 182881520, 208902766788, 260420548144996, 924, 2801708, 12244184472, 61756221742966, 341816489625522032, 1999206934751133055518 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..21.

V. Kaibel and G. M. Ziegler, Counting Lattice Triangulations, arXiv:math/0211268 [math.CO], 2002.

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).

Row sums: A151686. - N. J. A. Sloane, Jun 02 2009

Sequence in context: A134706 A145756 A030170 * A139695 A241590 A052522

Adjacent sequences:  A082637 A082638 A082639 * A082641 A082642 A082643

KEYWORD

nonn,tabl

AUTHOR

Ralf Stephan, May 15 2003

STATUS

approved

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Last modified April 20 14:27 EDT 2019. Contains 322310 sequences. (Running on oeis4.)