Combinatorics

1 Introduction
2 What Is Combinatorics?
3 Permutations and Combinations
4 The Pigeonhole Principle
5 Generating Permutations and Combinations
6 The Binomial Coefficients
7 The Inclusion-Exclusion Principle and Applications
8 Recurrence Relations and Generating Functions
9 Special Counting Sequences
10 Systems of Distinct Representatives
11 Combinatorial Designs
12 Introduction to Graph Theory
13 More on Graph Theory
14 Digraphs and Networks
15 Poĺya Counting
Dependency graph

1 Introduction

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