Given algorithm, Whats the time complexity of it? Given algorithm:

The inner loop is:

And the outer loop is: $\frac{n(n+1)}{2} * n$  but in the answer is says that I don't need to multiply it by $n$. Can anyone explain why the series is enough for the two outer for loops?

Outer loop complexity:
$$\sum_{i=1}^n\sum_{j=1}^i1=\sum_{i=1}^ni=\frac{n(n+1)}{2}$$
