| MSC 1991 | Number of Preprints | |
| 05-XX | Combinatorics
| 13 | browse |
| 05-00 | General reference works (handbooks, dictionaries, bibliographies, etc.)
| 13 | browse |
| 05-01 | Instructional exposition (textbooks, tutorial papers, etc.)
| 13 | browse |
| 05-02 | Research exposition (monographs, survey articles)
| 13 | browse |
| 05-03 | Historical
| 13 | browse |
| 05-04 | Explicit machine computation and programs (not the theory of computation or programming)
| 13 | browse |
| 05-06 | Proceedings, conferences, collections, etc.
| 13 | browse |
| 05Axx | Classical combinatorial problems
| 42 | browse |
| 05Bxx | Designs and configurations
| 283 | browse |
| 05Cxx | Graph theory
| 621 | browse |
| 05Dxx | Extremal combinatorics
| 6 | browse |
| 05Exx | Algebraic combinatorics
| 19 | browse |