English

Generating Functions for Domino Matchings in the $2\times k$ Game of Memory

Combinatorics 2020-01-01 v2

Abstract

When all the elements of the multiset {1,1,2,2,3,3,,k,k}\{1,1,2,2,3,3,\ldots,k,k\} are placed in the cells of a 2×k2\times k rectangular array, in how many configurations are exactly vv of the pairs directly over top one another, and exactly hh directly beside one another --- thus forming 2×12\times 1 or 1×21\times 2 dominoes? We consider the sum of matching numbers over the graphs obtained by deleting hh horizontal and vv vertical vertex pairs from the 2×k2\times k grid graph in all possible ways, providing a generating function for these aggregate matching polynomials. We use this result to derive a formal generating function enumerating the domino matchings, making connections with linear chord diagrams.

Keywords

Cite

@article{arxiv.1905.13165,
  title  = {Generating Functions for Domino Matchings in the $2\times k$ Game of Memory},
  author = {Donovan Young},
  journal= {arXiv preprint arXiv:1905.13165},
  year   = {2020}
}

Comments

v2, 16 pages, 8 figures, version published in the Journal of Integer Sequences