Problem Statement
Let $A\subset\mathbb{N}$ be an additive basis of order $k$ which is minimal, in the sense that if $B\subset A$ is any infinite set then $A\backslash B$ is not a basis of order $k$.
Must there exist an infinite $B\subset A$ such that $A\backslash B$ is a basis of order $k+1$?
Must there exist an infinite $B\subset A$ such that $A\backslash B$ is a basis of order $k+1$?
Categories:
Number Theory Additive Basis
Progress
Source: erdosproblems.com/881 | Last verified: January 19, 2026