On some properties of dispersion of block sequences of positive integers
On subseries.
On Subseries of Divergent Series
On sum-sets and product-sets of complex numbers
We give a simple argument that for any finite set of complex numbers , the size of the the sum-set, , or the product-set, , is always large.
On the class of all reciprocal bases for integers.
On the divisibility properties of integers (I)
On the prime density of Lucas sequences
The density of primes dividing at least one term of the Lucas sequence , defined by and for , with an arbitrary integer, is determined.
On the quotient sequence of sequences of integers
On the roots of certain sequences of congruences
On the statistical and σ-cores
In [11] and [7], the concepts of σ-core and statistical core of a bounded number sequence x have been introduced and also some inequalities which are analogues of Knopp’s core theorem have been proved. In this paper, we characterize the matrices of the class and determine necessary and sufficient conditions for a matrix A to satisfy σ-core(Ax) ⊆ st-core(x) for all x ∈ m.
On the subsequence of primes having prime subscripts.
On weighted densities
The continuity of densities given by the weight functions , , with respect to the parameter is investigated.
Orthogonal systems in vector spaces over finite fields.