Sites referring to open problems in mathematical research. Those referring to a specific area should be submitted to that category: there is also a recreational category.
Related categories 1
In various subjects, compiled by Torsten Sillke.
Most Wanted List
Elementary unsolved problems in mathematics, listed at the MathPages archive.
Open Problem Garden
A collection of unsolved math problems anyone can contribute to.
Unsolved Problem of the Week Archive
A list of unsolved problems published by MathPro Press during 1995.
A list compiled by Eric Weisstein in MathWorld.
Other languages 1
Last update:June 29, 2014 at 5:15:05 UTC