Peter Tittmann has authored 2 sequences.
A080690
Number of acyclic orientations of n X n grid graph.
Original entry on oeis.org
1, 14, 2398, 5015972, 128091434266, 39931856138212664, 151966368274993474937668, 7059965159455454640307807067492, 4003910412343921295679925280332950062686, 27719972687144020161876951888422165049044889741764
Offset: 1
Andre Poenitz [André Pönitz], Peter Tittmann (poenitz(AT)htwm.de), Mar 03 2003
- 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)]
A080691
Number of spanning forests of the n X n grid graph.
Original entry on oeis.org
1, 15, 3102, 8790016, 341008617408, 181075508242067552, 1315927389374152034113856, 130877523274817580209987036404864, 178135975585132088643635627145305047963624, 3318089946193080260596185780557019330240985991363200, 845810281460839114896541390288164525407725177643901666416522016
Offset: 1
- Andrew Howroyd, Table of n, a(n) for n = 1..15
- 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)]
- Eric Weisstein's World of Mathematics, Grid Graph