Sum-free set
In additive combinatorics and number theory, a subset A of an abelian group G is said to be sum-free if the sumset A + A is disjoint from A. In other words, A is sum-free if the equation a + b = c {\displaystyle a+b=c} has no solution with a , b , c ∈ A {\displaystyle a,b,c\in A} . For example, the set of odd numbers is a sum-free subset of the integers, and the set {N + 1, ..., 2N} forms a large sum-free subset of the set {1, ..., 2N}.