Domino Tilings of 2 × n Grids (or Perfect Matchings of Grid Graphs) on Surfaces
sarah-marie belcastro
Mathematical Staircase, Inc.
Holyoke, MA 01040
USA
and
Department of Mathematical Sciences
Smith College
Northampton, MA 01063
USA
Abstract:
It is well known that the number of edge-labeled perfect matchings
of a 2 × n planar grid graph is the (n + 1)st Fibonacci number. The
number of edge-labeled perfect matchings of grid graphs on surfaces has
been computed using Pfaffians, matching polynomials, and generating
functions. Here we present an elegant and elementary approach to
enumerating edge-labeled perfect matchings of n grid graphs on surfaces
representable by opposite-edge-identified quadrilaterals. For simplicity
in description, we give proofs using the language of tilings of grids.
Full version: pdf,
dvi,
ps,
latex,
Mathematica notebook
(Concerned with sequences
A000032
A000045
A000129
A000204
A000211
A001835
A003499
A005248
A020878
A048788
A052530
A068397
A079935
A103997
A162483
A162484
A162485
A351635.)
Received July 17 2009; revised versions received February 16 2022; February 7 2023; April 11 2023.
Published in Journal of Integer Sequences,
June 7 2023.
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