These proceedings consist of several articles based on talks given at the "Integers Conference 2011" in the area of combinatorial number theory. They contain articles, which are expanded and revised versions of talks given by leading researchers. The articles present a range of important and modern research topics in the areas of number theory and combinatorics, such as partition theory, combinatorial game theory, Ramsey theory, additive number theory, multiplicative number theory, sequences, and other topics. The book is aimed at allmathematicians interested innumber theory and combinatorics, from graduate students through senior mathematicians.