The Schnirelmann density of a set of natural numbers A is defined as
where A(n) denotes the number of elements of A not exceeding n and inf is infimum.
The Schnirelmann density is well-defined even if the limit of A(n)/n as n → ∞ fails to exist (see asymptotic density).
Read more about Schnirelmann Density: Properties, Schnirelmann's Theorems, Additive Bases, Mann's Theorem, Waring's Problem, Schnirelmann's Theorem, Essential Components