%0 Journal Article %T Gaps and the exponent of convergence of an integer sequence %A Georges Grekos %A Martin Sleziak %A Jana Tomanov¨˘ %J Uniform Distribution Theory %D 2011 %I Mathematical Institute of the Slovak Academy of Sciences %X Professor Tibor al¨˘t, at one of his seminars at Comenius University, Bratislava, asked to study the influence of gaps of an integer sequence $A={a_1 < a_2 < \dots < a_n < \dots}$ on its exponent of convergence. The exponent of convergence of $A$ coincides with its upper exponential density. In this paper we consider an extension of Professor al¨˘t's question and we study the influence of the sequence of ratios $({\frac{a_m}{a_{m+1}}})_{m=1}^\infty}$ and of the sequence $({\frac{a_{m+1}-a_m}{a_{m}}})_{m=1}^\infty}$ on the upper and on the lower exponential densities of $A$. %K Integer sequence %K densities %K exponent of convergence %U http://www.boku.ac.at/MATH/udt/vol06/no2/09GreSlTo11-2.pdf