In a recent paper Merino and Welsh (1999) studied several counting problems on the square lattice Ln. There the authors gave the following bounds for the asymptotics of f(n), the number of forests of Ln ,a nd(n), the number of acyclic orienta
['Neil J. Calkin', 'Criel Merino', 'Steven D. Noble', 'Marc Noy']
Improved Bounds for the Number of Forests and Acyclic Orientations in the Square Lattice