On a class of arithmetic convolutions involving arbitrary sets of integers.
On a class of arithmetical functions connected with multiplicative functions.
On a conjecture of Erdös
On a conjecture of Issai Schur.
On a conjecture of Mąkowski and Schinzel concerning the composition of the arithmetic functions σ and ϕ
For any positive integer n let ϕ(n) and σ(n) be the Euler function of n and the sum of divisors of n, respectively. In [5], Mąkowski and Schinzel conjectured that the inequality σ(ϕ(n)) ≥ n/2 holds for all positive integers n. We show that the lower density of the set of positive integers satisfying the above inequality is at least 0.74.
On a conjecture of Narkiewicz about functions with non-decreasing normal order
On a conjecture of Pomerance
On a density problem of Erdös
On a divisor problem related to the Epstein zeta-function, IV
On a generalization of a formula of Sierpiński.
On a generalization of a formula of Sierpiński. II.
On a kind of generalized Lehmer problem
For , let be fixed numbers of the set , and let
On a kind of uniform distribution of values of multiplicative functions in residue classes
On a method of Balasubramanian and Ramachandra (on the abelian group problem)
On a multiplicative hybrid problem
On a multiplicative partition function.
On a new analytical method and its applications
On a new method in the analysis with applications
On a Problem Concerning Two Integer Sequences
On a Problem of A. Rényi.