3. For what value of the parameter $a$ does the domain of the function $f(x)=a^{2}+4 a+2-\ln ^{2}(x-a)$ and the set of its values not intersect and together cover the entire number line?

If there are multiple possible answers, list them in any order separated by a semicolon.
Answer: $-1 ;-2\|-2 ;-1\|-1,-2 \|-2 ;-1$