On the fast Khintchine spectrum in continued fractions

Fan Ai-Hua, Lingmin Liao, Bao-Wei Wang +1

For $x\in [0,1)$, let $x=[a_1(x),a_2(x),...]$ be its continued fraction expansion with partial quotients $a_n(x),n\ge 1$. Let $\psi :\mathbb{N}\to \mathbb{N}$ be a functi…