On generalized lacunary series

Grigori A. Karagulyan, Vahe G. Karagulyan

Given lacunary sequence of integers, $n_k$, $n_{k+1}/n_k>\lambda >1$, we define a new sequence $\{m_k\}$ formed by all possible $l$-wise sums $\pm n_{k_1}\pm n_{k_2}\pm \dots \pm n_{k_l}$…