User Gerhard Paseman

15 votes

Examples of seemingly elementary problems that are hard to solve?

answered Sep 18, 2011 at 6:46

10 votes

What are your favorite puzzles/toys for introducing new mathematical concepts to students?

answered Aug 14, 2010 at 22:21

9 votes

How to escape the inclination to be a universalist or: How to learn to stop worrying and do some research.

answered Aug 17, 2010 at 16:13

9 votes

What's a magical theorem in logic?

answered Aug 30, 2011 at 0:35

8 votes

Giving a math talk with no blackboard or projector

answered Sep 14, 2011 at 17:54

6 votes

Maiden Names vs. Married Names

answered Aug 31, 2011 at 16:38

6 votes

Sieve of Erathostenes: removing consecutive items

answered Dec 8, 2012 at 23:07

6 votes

Excellent mathematical explanations

answered Dec 19, 2012 at 4:24

5 votes

find the collision of a particle with a swept triangle.

answered Jan 23, 2010 at 23:29

5 votes

Accepted

How many binary operations are associative?

answered Oct 22, 2012 at 0:22

4 votes

Thom's Principle: rich structures are more numerous in low dimension

answered Sep 13, 2011 at 16:33

4 votes

Large Intersecting Subsets of a Set

answered Oct 24, 2012 at 5:04

3 votes

Can pure mathematics harness citizen science?

answered Nov 18, 2012 at 19:56

3 votes

Accepted

What is the number of $2n\times 2n$-matrices $g=\begin{pmatrix} A & B \\\ C & -A^{t} \end{pmatrix}$, $B$ and $C$ symmetric, over the finite field $\mathbb{F}\_{q}$ with $\mathrm{rank}(g)=k$?

answered Nov 7, 2012 at 18:00

3 votes

Fast matrix multiplication

answered Aug 2, 2010 at 0:26

3 votes

Walking around Santa Cruz, track around the soccer field

answered Aug 16, 2010 at 1:57

3 votes

Analogues of Jacobsthal's function

answered Oct 22, 2012 at 21:43

2 votes

partly obscured Rubik's cube

answered Oct 10, 2012 at 4:14

2 votes

Threading pinholes in the wall of cylinder to pass through an internal coordinate

answered Oct 2, 2011 at 20:37

2 votes

What is the smallest rectangle that will contain all squares of size 1 to 33?

answered Oct 3, 2011 at 4:34

2 votes

Unmathematical habits of thought and action which would be of use to mathematicians

answered Sep 8, 2011 at 16:33

2 votes

Erik Westzynthius's cool upper bound argument: update?

answered Sep 8, 2011 at 19:18

2 votes

Believing the Conjectures

answered Oct 25, 2012 at 16:32

2 votes

Smallest square to wrap a cylinder

answered Dec 25, 2012 at 23:46

2 votes

Math for a cake

answered Dec 29, 2012 at 19:45

2 votes

power of adjacency matrix

answered Jan 4, 2013 at 3:02

2 votes

Provided a list of sets, $L$, computing an array where each entry $q_i \in Q$ is the family of sets in $L$ that have intersection $k$ with $l_i \in L$

answered Oct 21, 2012 at 7:02

2 votes

Positive results coming from paradoxes

answered Dec 15, 2012 at 18:31

1 vote

What is the maximal sparsity of a matrix?

answered Jan 15, 2013 at 18:08

1 vote

Hamiltonian cycles in power-graphs

answered Jan 17, 2013 at 13:34

Stack Exchange Network

58 Answers

Examples of seemingly elementary problems that are hard to solve?

What are your favorite puzzles/toys for introducing new mathematical concepts to students?

How to escape the inclination to be a universalist or: How to learn to stop worrying and do some research.

What's a magical theorem in logic?

Giving a math talk with no blackboard or projector

Maiden Names vs. Married Names

Sieve of Erathostenes: removing consecutive items

Excellent mathematical explanations

find the collision of a particle with a swept triangle.

How many binary operations are associative?

Thom's Principle: rich structures are more numerous in low dimension

Large Intersecting Subsets of a Set

Can pure mathematics harness citizen science?

What is the number of $2n\times 2n$-matrices $g=\begin{pmatrix} A & B \\\ C & -A^{t} \end{pmatrix}$, $B$ and $C$ symmetric, over the finite field $\mathbb{F}\_{q}$ with $\mathrm{rank}(g)=k$?

Fast matrix multiplication

Walking around Santa Cruz, track around the soccer field

Analogues of Jacobsthal's function

partly obscured Rubik's cube

Threading pinholes in the wall of cylinder to pass through an internal coordinate

What is the smallest rectangle that will contain all squares of size 1 to 33?

Unmathematical habits of thought and action which would be of use to mathematicians

Erik Westzynthius's cool upper bound argument: update?

Believing the Conjectures

Smallest square to wrap a cylinder

Math for a cake

power of adjacency matrix

Provided a list of sets, $L$, computing an array where each entry $q_i \in Q$ is the family of sets in $L$ that have intersection $k$ with $l_i \in L$

Positive results coming from paradoxes

What is the maximal sparsity of a matrix?

Hamiltonian cycles in power-graphs