[Euler's number](https://en.wikipedia.org/wiki/E_(mathematical_constant)) $e$ is the base of the [[natural logarithm]]. It can be calculated as the limit of $(1 + 1/n)^n$ as $n$ approaches infinity or the sum of the infinite series $e=\sum_{n-0}^\infty\frac{1}{n!}$ The approximate value is $2.71828$. ## R To find Euler's number in R use `exp(1)`. This works because `exp` is the exponential function with base $e$. To get $e^2$, use `exp(2)`.