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A080690
Number of acyclic orientations of n X n grid graph.
4
1, 14, 2398, 5015972, 128091434266, 39931856138212664, 151966368274993474937668, 7059965159455454640307807067492, 4003910412343921295679925280332950062686, 27719972687144020161876951888422165049044889741764
OFFSET
1,2
LINKS
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.
Peter Tittmann, More Results [Gives a(1)-a(14)]
CROSSREFS
Sequence in context: A279577 A015515 A183580 * A268424 A079918 A199648
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