Published online by Cambridge University Press: 20 November 2018
Let $\lambda $ be a fixed integer exceeding 1 and ${{s}_{n}}$ any strictly increasing sequence of positive integers satisfying ${{s}_{n}}\le {{n}^{15/14+o(1)}}$. In this paper we give a version of the large sieve inequality for the sequence ${{\lambda }^{{{s}_{n}}}}$. In particular, we obtain nontrivial estimates of the associated trigonometric sums “on average” and establish equidistribution properties of the numbers ${{\lambda }^{{{s}_{n}}}},n\le p{{(\log p)}^{2+\varepsilon }}$, modulo $p$ for most primes $p$.