A080690 Number of acyclic orientations of n X n grid graph.

1, 14, 2398, 5015972, 128091434266, 39931856138212664, 151966368274993474937668, 7059965159455454640307807067492, 4003910412343921295679925280332950062686, 27719972687144020161876951888422165049044889741764

Offset

1,2

Links

Table of n, a(n) for n=1..10.

N. Calkin, C. Merino, S. Noble and M. Noy, Improved Bounds for the Number of Forests and Acyclic Orientations in the Square Lattice, The Electronic Journal of Combinatorics, Volume 10(1), 2003, #R4.

A. Pönitz, Über eine Methode zur Konstruktion von Algorithmen für die Berechnung von Invarianten in endlichen ungerichteten Hypergraphen, PhD Thesis (2004) C.3.

Peter Tittmann, More Results [Gives a(1)-a(14)]

Crossrefs

Cf. A007341, A080691.

Sequence in context: A279577 A015515 A183580 * A268424 A079918 A199648

Adjacent sequences: A080687 A080688 A080689 * A080691 A080692 A080693

Keyword

nonn

Author

Andre Poenitz [André Pönitz], Peter Tittmann (poenitz(AT)htwm.de), Mar 03 2003

Extensions

a(10) from Alois P. Heinz, Dec 21 2013

Status

approved