19 Answers votes newest views recent 1Difficult examples for Frankl’s union-closed conjecture 2Elementary+Short+Useful 14A Book You Would Like to Write 3Computer Science for Mathematicians 7What would you want to see at the Museum of Mathematics? 0Ingenuity in mathematics 5How To Present Mathematics To Non-Mathematicians? 8Suggestions for good notation 27Most memorable titles 4Combinatorial results without known combinatorial proofs 1Pacing for learning new material 1Most harmful heuristic? 0Math puzzles for dinner 1Is monomorphism going in both directions sufficient for isomorphism? 31Examples of common false beliefs in mathematics. 8Is there a general setting for self-reference? 9Collection of equivalent forms of Riemann Hypothesis 9Thinking and Explaining 3Which mathematical ideas have done most to change history?