Question 4
Find the positive integer $n$ for which $$
\begin{aligned}&\lfloor\log_2 1\rfloor+\lfloor\log_2 2\rfloor+\lfloor\log_2 3\rfloor\\&\quad+\cdots+\lfloor\log_2 n\rfloor=1994.\end{aligned}
$$ (For real $x,$ $\lfloor x\rfloor$ is the greatest integer not exceeding $x.$)
\begin{aligned}&\lfloor\log_2 1\rfloor+\lfloor\log_2 2\rfloor+\lfloor\log_2 3\rfloor\\&\quad+\cdots+\lfloor\log_2 n\rfloor=1994.\end{aligned}
$$ (For real $x,$ $\lfloor x\rfloor$ is the greatest integer not exceeding $x.$)