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Abstract: Text: For each positive integer m, let , , where and A is a subset of . Recently Chen proved that for each positive integer m, there exists a set such that and for any . In this paper, the following results are proved: (i) for each positive integer m, there exists a set such that and for all with at most 3 exceptions; (ii) for each positive integer m, there exists a set with and such that and for all with at most 3 exceptions. Video: For a video summary of this paper, please click here or visit http://www.youtube.com/watch?v=GfZ07Fg5qXE. [Copyright &y& Elsevier]

Abstract: In this paper we study generalised prime systems for which the integer counting function is asymptotically well behaved, in the sense that , where ρ is a positive constant and . For such systems, the associated zeta function is holomorphic for . We prove that for , for any , and also for for all such σ except possibly one value. The Dirichlet divisor problem for generalised integers concerns the size of the error term in , which is for some . Letting denote the infimum of such θ, we show that . [Copyright &y& Elsevier]

Abstract: In this paper, we determine the closure in the full topology over of the set , where is a nondegenerate binary recurrent sequence with integer coefficients whose characteristic roots are quadratic units. This generalizes the result for the case when was the nth Fibonacci number. [Copyright &y& Elsevier]

Abstract: In this paper we give irrationality results for numbers of the form where the numbers behave like a geometric progression for a while. The method is elementary, not using differentiation or integration. In particular, we derive elementary proofs of the irrationality of π and for Gaussian integers . [Copyright &y& Elsevier]

Abstract: We call a set A of positive integers an asymptotic basis of order h if every sufficiently large integer n can be written as a sum of h elements of A. If no proper subset of A is an asymptotic basis of order h, then A is a minimal asymptotic basis of that order. Erdős and Nathanson showed that for every there exists a minimal asymptotic basis A of order h with , where denotes the density of A. Erdős and Nathanson asked whether it is possible to strengthen their result by deciding on the existence of a minimal asymptotic bases of order such that . Moreover, they asked if there exists a minimal asymptotic basis with . In this paper we answer these questions in the affirmative by constructing a minimal asymptotic basis A of order 2 fulfilling a very restrictive condition [Copyright &y& Elsevier]

Abstract: In this paper we develop a method for determining the number of integers without large prime factors lying in a given set S. We will apply it to give an easy proof that certain sufficiently dense sets A and B always produce the expected number of “smooth” sums , , . The proof of this result is completely combinatorial and elementary. [Copyright &y& Elsevier]

Abstract: In this paper, we study the function , which associates to every pair of positive integers a and b the number of positive integers c such that the triangle of sides a, b and c is Heron, i.e., it has integral area. In particular, we prove that if p and q are primes, and that for a random choice of positive integers a and b. [Copyright &y& Elsevier]