The fifth International Combinatorics Olympiad (ICO 2025) took place in Tehran on October 30 and 31, bringing together approximately 5,000 competitors from over 70 countries both in person and online.

Abstract: This chapter contains sections titled: Composition: Some Historical Models, The Celestial Model, The Empirical Model, The Dialectical Model, The Gestalt Model, The Cognitive Model, ...

Welcome to Combinatorics and Optimization The C&O department has 36 faculty members and 60 graduate students. We are intensely research oriented and hold a strong international reputation in each of ...

An illustration of a magnifying glass. An illustration of a magnifying glass.

The massive capacity of today's sequencing machines can be harnessed efficiently by sequencing pooled samples and decoding the results. The new sequencing technologies will have many applications 3, ...

This is a textbook for an introductory combinatorics course lasting one or two semesters. An extensive list of problems, ranging from routine exercises to research questions, is included. In each ...

Prerequisites: Graduate standing or consent of instructor. Many students find this course difficult, so a first-rate math background is highly recommended. See the Review Sheet for material you're ...

This course is an introduction to combinatorics with a focus that includes graph theory. Specific topics covered are enumerative combinatorics up to inclusion-exclusion, the theory of simple graphs, ...