User Brendan McKay

75 votes

Awfully sophisticated proof for simple facts

answered Feb 24, 2013 at 7:35

64 votes

Accepted

Non-enumerative proof that there are many derangements?

answered Jan 20, 2012 at 12:26

60 votes

What advantage humans have over computers in mathematics?

answered Mar 13, 2016 at 9:08

43 votes

Accepted

A conjecture on planar graphs

answered Jul 4, 2017 at 22:16

37 votes

Accepted

How many $p$-regular graphs with $n$ vertices are there?

answered Oct 10, 2011 at 23:21

31 votes

Titles composed entirely of math symbols

answered Dec 16, 2011 at 7:33

29 votes

Examples of seemingly elementary problems that are hard to solve?

answered Sep 18, 2011 at 4:03

28 votes

Accepted

Is there a graph with 99 vertices in which every edge belong to a unique triangle and every nonedge to a unique quadrilateral?

answered Apr 6, 2014 at 9:55

28 votes

Is it easy to produce hard-to-color graphs?

answered May 30, 2014 at 23:22

28 votes

How come mathematicians published in Annals of Eugenics?

answered May 8, 2019 at 11:56

26 votes

Accepted

Formal writing: numbers under 10

answered Mar 6, 2013 at 12:30

25 votes

Accepted

Counting 2m X 2m 0-1 matrices with m ones in each row and each column.

answered Dec 9, 2013 at 1:04

24 votes

Accepted

A conjectural infinite series for $\frac{\pi^2}{5\sqrt{5}}$

answered Sep 2, 2021 at 6:13

23 votes

Accepted

Determining if some permutation of a vector satisfies a system of linear equations

answered Aug 3, 2018 at 11:50

23 votes

Recent observation of gravitational waves

answered Feb 13, 2016 at 22:09

22 votes

Mathematical habits of thought and action which would be of use to non-mathematicians

answered Sep 8, 2011 at 5:58

21 votes

Composition of Derangements

answered Nov 1, 2016 at 8:39

21 votes

Examples of errors in computational combinatorics results

answered Jan 11 at 14:09

18 votes

Reasons for difficulty of Graph Isomorphism and why Johnson graphs are important?

answered Jan 4, 2016 at 8:10

18 votes

Dealing with unwanted co-authorship requests

answered Nov 24, 2017 at 3:20

18 votes

How to write an abstract for a math paper?

answered Jun 28, 2015 at 16:24

17 votes

Algorithms for calculating R(5,5) and R(6,6)

answered Jul 3, 2015 at 12:53

16 votes

Is there a Cayley graph of a non-abelian finite group that is not isomorphic to any Cayley graph of any abelian group?

answered Aug 26, 2013 at 23:58

16 votes

Regular graph of order 50, degree 7 and Automorphism group of order 288000. How to check if it is Cayley

answered Jun 2, 2012 at 5:52

16 votes

What is the upper bound of $R\underbrace{(3,3,3, \ldots,3)}_\text{$k$ times}$?

answered Apr 15, 2017 at 9:26

16 votes

Accepted

What happens to eigenvalues when edges are removed?

answered Jan 29, 2020 at 9:21

15 votes

Accepted

Are all cubic graphs almost Hamiltonian?

answered Feb 4, 2019 at 6:40

15 votes

Accepted

Why does an invertible complex symmetric matrix always have a complex symmetric square root?

answered Nov 20, 2020 at 12:37

15 votes

Sum of 'the first k' binomial coefficients for fixed $N$

answered Nov 11, 2015 at 13:38

15 votes

Accepted

The Simultaneous Conjugacy Problem in the symmetric group $S_N$

answered Apr 4, 2014 at 16:25

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591 Answers

Awfully sophisticated proof for simple facts

Non-enumerative proof that there are many derangements?

What advantage humans have over computers in mathematics?

A conjecture on planar graphs

How many $p$-regular graphs with $n$ vertices are there?

Titles composed entirely of math symbols

Examples of seemingly elementary problems that are hard to solve?

Is there a graph with 99 vertices in which every edge belong to a unique triangle and every nonedge to a unique quadrilateral?

Is it easy to produce hard-to-color graphs?

How come mathematicians published in Annals of Eugenics?

Formal writing: numbers under 10

Counting 2m X 2m 0-1 matrices with m ones in each row and each column.

A conjectural infinite series for $\frac{\pi^2}{5\sqrt{5}}$

Determining if some permutation of a vector satisfies a system of linear equations

Recent observation of gravitational waves

Mathematical habits of thought and action which would be of use to non-mathematicians

Composition of Derangements

Examples of errors in computational combinatorics results

Reasons for difficulty of Graph Isomorphism and why Johnson graphs are important?

Dealing with unwanted co-authorship requests

How to write an abstract for a math paper?

Algorithms for calculating R(5,5) and R(6,6)

Is there a Cayley graph of a non-abelian finite group that is not isomorphic to any Cayley graph of any abelian group?

Regular graph of order 50, degree 7 and Automorphism group of order 288000. How to check if it is Cayley

What is the upper bound of $R\underbrace{(3,3,3, \ldots,3)}_\text{$k$ times}$?

What happens to eigenvalues when edges are removed?

Are all cubic graphs almost Hamiltonian?

Why does an invertible complex symmetric matrix always have a complex symmetric square root?

Sum of 'the first k' binomial coefficients for fixed $N$

The Simultaneous Conjugacy Problem in the symmetric group $S_N$