8 Answers votes newest views recent 12Are there any non-planar graphs containing only K(3,3) as a subgraph that are not 4-colourable? 3On a special kind of graph connectig n point to n points. 9NP-Hard solution question 14Most harmful heuristic? 1Where can I find questions motivating important ideas in math? 0Alternatives to pi day 11Do good math jokes exist? 1Text for an introductory Real Analysis course.