Mathematical notation of set with $n+3$ members One of the math problems I have describes a set of numbers this way:

let there be a set A such that $A=\{{1,2,3,...,n+3}\}$.

I don't understand what the $n+3$ means and how the set actually looks like.

$n$ is just a natural number. So the set is of variable length. For example choosing $n=2$ yields $$A =\{1,2,3,4,5\}$$
