To cite package ‘combinatorics’ in publications use:

Paul A (2022). combinatorics: Introduction to Some Combinatorial Relations. R package version 0.1.0, https://CRAN.R-project.org/package=combinatorics.

Corresponding BibTeX entry:

  @Manual{,
    title = {combinatorics: Introduction to Some Combinatorial
      Relations},
    author = {Anik Paul},
    year = {2022},
    note = {R package version 0.1.0},
    url = {https://CRAN.R-project.org/package=combinatorics},
  }