Is the Fibonacci sequence exponential?
The Fibonacci Sequence does not take the form of an exponential $b^n$, but it does exhibit exponential growth. Binet's formula for the $n$th Fibonacci number is $$F_n=\frac{1}{\sqrt{5}}\bigg(\frac{1+\sqrt 5}{2}\bigg)^n-\frac{1}{\sqrt{5}}\bigg(\frac{1-\sqrt 5}{2}\bigg)^n$$ Which shows that, for large values of $n$, the Fibonacci numbers behave approximately like the exponential $F_n\approx \frac{1}{\sqrt{5}}\phi^n$.