Counting graded lattices of rank 3 that have few coatoms

  title={Counting graded lattices of rank 3 that have few coatoms},
  author={Jukka Kohonen},
  journal={Int. J. Algebra Comput.},
  • J. Kohonen
  • Published 2019
  • Mathematics, Computer Science
  • Int. J. Algebra Comput.
We consider the problem of computing [Formula: see text], the number of unlabeled graded lattices of rank [Formula: see text] that contain [Formula: see text] coatoms and [Formula: see text] atoms. More specifically, we do this when [Formula: see text] is fairly small, but [Formula: see text] may be large. For this task, we describe a computational method that combines constructive listing of basic cases and tools from enumerative combinatorics. With this method, we compute the exact values of… Expand

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