Brendan McKay's user avatar
Brendan McKay's user avatar
Brendan McKay's user avatar
Brendan McKay
  • Member for 13 years, 7 months
  • Last seen this week
75 votes

Awfully sophisticated proof for simple facts

64 votes
Accepted

Non-enumerative proof that there are many derangements?

60 votes

What advantage humans have over computers in mathematics?

43 votes
Accepted

A conjecture on planar graphs

37 votes
Accepted

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

32 votes

Titles composed entirely of math symbols

30 votes

Examples of seemingly elementary problems that are hard to solve?

29 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?

28 votes

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

28 votes

How come mathematicians published in Annals of Eugenics?

26 votes
Accepted

Formal writing: numbers under 10

25 votes
Accepted

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

24 votes
Accepted

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

23 votes
Accepted

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

23 votes

Recent observation of gravitational waves

23 votes

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

21 votes

Composition of Derangements

21 votes

Examples of errors in computational combinatorics results

18 votes

Dealing with unwanted co-authorship requests

18 votes

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

18 votes

How to write an abstract for a math paper?

17 votes

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

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?

16 votes

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

16 votes

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

16 votes
Accepted

What happens to eigenvalues when edges are removed?

16 votes

Are (55, 165, 495, 1485) and (286, 1716, 10296, 61776) the only geometric sequences of length 4 among non-trivial binomials?

15 votes
Accepted

Are all cubic graphs almost Hamiltonian?

15 votes
Accepted

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

15 votes

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

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