Can this expression be simplified?
$ \sum_{i=0}^n (k^i)/i! $
EDIT: This expression I have got as the number of possible ways to select n objects or less from k different infinite objects (you can select as many as you can from any type)...
I believe it must be equal to the number of possible ways to select n objects from k+1 different infinite objects, where the extra +1 is a dummy object, selecting one of this type means letting an empty space in the final selection (i.e. selecting n-1 not n)...
so this must be equal to:
$ (k+1)^n/n! $
Why that is not right??