Open Mathematical Questions - http://www.jdawiseman.com/papers/easymath/open_questions.html
A few unsolved mathematical questions put together by Julian D. A. Wiseman. |
Open Problems for Undergraduates - http://dimacs.rutgers.edu/~hochberg/undopen/
A collection of open problems in Discrete Mathematics which are currently being researched by members of the DIMACS community. |
Open Problems in Combinatorics - http://www.combinatorics.net/problems/
Features links to newsletters, workshops, and papers. |
Past Open Problems - http://www.math.uiuc.edu/~west/pcol/pcolink.html
From the SIAM Activity Group Newsletter in Discrete Mathematics. In PostScript. Compiled by Douglas B. West. |
Problems in Graph Theory and Combinatorics - http://www.math.uiuc.edu/~west/openp/
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. |