Combinatorics Problems
Combinatorics problems selected from math olympiads.
Josh Cooper's Math Pages : Open Combinatorics
Offers descriptions of discrepancy, Euclidean Ramsey Theory, geometric graphs and hypergraphs.
Open Problems for Undergraduates
A collection of open problems in Discrete Mathematics which are currently being researched by members of the DIMACS community.
Open Problems in Combinatorics
Features links to newsletters, workshops, and papers.
Open Problems in Discrete Mathematics
From the SIAM DM activity group newsletter and other sources.
Past Open Problems
From the SIAM Activity Group Newsletter in Discrete Mathematics. In PostScript. Compiled by Douglas B. West.
Problem Collection in Combinatorial Optimization
Maintained by the EGRES group. HTML/LaTeX/text format.
Problems in Graph Theory and Combinatorics
A collection maintained by Douglas B. West, of the University of Illinois. Features brief introductions, along with references cited. Topics include matching and independence, connectivity, graph homomorphism and circular coloring.
Some Problems in Matroid Theory
Thomas Zaslavsky of Binghamton State University of New York presents brief descriptions and references. Find information on Bonin's Projective Bound including the maximum r-flat, covering and packing by flats.