I researched the irrational number e, which the first few digits are 2.7182818284590452353602874713527, but is known to have over 1 trillion digits of accuracy. It is also known as Euler’s number, which is where the symbol e is from, after Leonhard Euler. He used e as the base for natural logarithms in 1731. However, it was first discovered by a guy named James Bernoulli when he was looking at the study of compound interest.
The value of e equals 1/0! + 1/1! + 1/2! + 1/3! + 1/4! + 1/5! + 1/6! + 1/7! + … And so on.
Resources:
http://www.mathsisfun.com/numbers/e-eulers-number.html