Sorry if this is the wrong forum.

Is there a "nice" formula for the following? :

$\displaystyle \sum_{k_2=0}^{k_1}\sum_{k_3=0}^{k_2}\sum_{k_4=0}^{ k_3} ... \sum_{k_n=0}^{k_{n-1}}1$

I do the first few iterations and it just seems to get messy :S

Thanks for any help