Several inequalities about the number of positive divisors of a natural number .
Sign changes of certain arithmetical function at prime powers
We examine an arithmetical function defined by recursion relations on the sequence and obtain sufficient condition(s) for the sequence to change sign infinitely often. As an application we give criteria for infinitely many sign changes of Chebyshev polynomials and that of sequence formed by the Fourier coefficients of a cusp form.
Sobre el cardinal de ciertos subconjuntos finitos del cuadrado unidad.
Some Arithmetic Sums Connected With the Greatest Integer Function.
Some characterizations of specially multiplicative functions.
Some characterizations of totients.
Some modular results on the Euler and Bernoulli polynomials
Some more remarks on arithmetical identities
Some problems in number theory that arise from group theory.
In this expository paper, we present several open problerns in number theory that have arisen while doing research in group theory. These problems are on arithmetical functions or partitions. Solving some of these problems would allow to solve some open problem in group theory.[Proceedings of the Primeras Jornadas de Teoría de Números (Vilanova i la Geltrú (Barcelona), 30 June - 2 July 2005)].
Some properties of the Euler quotient matrix.
Some properties of the series of composed numbers.
Some remark on Euler's φ function
Some remarks on a paper of L. Tóth.
Some remarks on the iterates of the φ and σ functions
Some remarks on two generalizations of Euler's theorem
Some results concerning exponential divisors.
Some results on the unitary analogue of the Lehmer problem.
Some special subsets of intervals of a locally finite locally semi-modular, local lattice.
Součet řady Lambertovy a počet dělitelů celistvého čísla
Sui numeri quasiperfetti