As the title suggests, I saw this question from a new user here. The question was closed as self-study and I can understand why...on the surface it appears to be asking for someone to solve the question for them:
However, what they are actually asking is what the notation is, which can be difficult to find given Euler's Number isn't something you can easily type into a Google search (googling "e" for example isn't helpful and the symbol $e$ doesn't make that any more useful). Does this count if they are just asking for what this symbol is? I think this question is somewhere in a gray area, but maybe I'm overlooking the problem. I don't have a hardline stance on the subject, just curious.