Top Posts
Recent comments
 Peter Cameron on New web address
 Peter Cameron on New web address
 dockie73 on New web address
 AMBAT VIJAYAKUMAR on George F. Simmons
 For DeepArcher « Log24 on George F. Simmons
Blogroll
 Astronomy Picture of the Day
 Azimuth
 British Combinatorial Committee
 Comfortably numbered
 Diamond Geezer
 Exploring East London
 From hill to sea
 Gödel's lost letter and P=NP
 Gil Kalai
 Jane's London
 Jon Awbrey
 Kourovka Notebook
 LMS blogs page
 Log24
 London Algebra Colloquium
 London Reconnections
 MathBlogging
 Micromath
 Neill Cameron
 neverendingbooks
 Noncommutative geometry
 numericana hall of fame
 Ratio bound
 Robert A. Wilson's blog
 Since it is not …
 Spitalfields life
 Sylvy's mathsy blog
 SymOmega
 Terry Tao
 The Aperiodical
 The De Morgan Journal
 The ICA
 The London column
 The Lumber Room
 The matroid union
 Theorem of the day
 Tim Gowers
 XKCD
Find me on the web

Join 664 other subscribers
Cameron Counts: RSS feeds
Meta
Tag Archives: Catalan numbers
A week in Vienna
Last week, in the second week of Spring break in St Andrews, I was in Vienna, giving a course of lectures to the PhD students, at the invitation of Tomack Gilmore, a Queen Mary undergraduate now finishing his PhD with … Continue reading
Advanced Combinatorics: the St Andrews lectures
Three years ago, when I joined the School of Mathematics and Statistics at the University of St Andrews, it was suggested that I might like to give a final year MMath module on “Advanced Combinatorics”. No compulsion. Well, of course … Continue reading
Posted in Lecture notes
Tagged Catalan numbers, chromatic polynomial, cycle index, doocot principle, enumeration, formal power series, Friendship Theorem, Gaussian coefficients, generalised line graphs, generalised quadrangles, IBIS groups, line graphs, Mathieu groups, matroid, Moebius inversion, orbitcounting lemma, projective planes, root systems, strongly regular graphs, symmetric Sudoku, triangle property, Tutte polynomial, weight enumerator
Leave a comment
Permutation patterns, day 1
Today is the first day of Permutation Patterns 15, at the London Mathematical Society headquarters in De Morgan House. Registration began at 8.30. I don’t like using the Underground at that time of day if it can be avoided; but … Continue reading
Bijective proofs
A fourth proof Last month I described three proofs of the formula for the number of ways to choose k objects from a set of n, if repetition is allowed and order is not significant; it is the same as … Continue reading
Posted in exposition, open problems
Tagged bijections, Catalan numbers, Catalan objects, Dima FonDerFlaass, permutations, sampling
Leave a comment