Answer
1 is not included as a logarithmic base since 1, raised to any power, is 1. If we tried to set $1^x=2$, we would find that there is no value for $x$ that would make the equation valid.
Work Step by Step
$log_b n=e$
$b^e =n$
$1^x=2$
There is no value for $x$ that would make $1^x=2$ valid.