Répartition des densités des sous-suites d'une suite d'entiers

AbstractLet A denote a strictly increasing sequence of integers; for any integer n, define A(n) to be the number of positive elements of A not exceeding n. The upper and lower asymptotic densities of A are defined by We describe the set of pairs (dB, dB), where B runs over all subsequences of A, as being a closed convex region of the plane. The converse statement is also proved