Add next value to total in excel?

Question

excel

Good evening. Suppose there are several rows, each with some number, for example:
1
2
3
4
5
I need the current cell's indicator in the adjacent column to be added to the total sum, for example:
1 - 1 (0 + 1)
2 - 3 ( 1+2)
3 - 6 (3+3)
4 - 10 (6+4)
5 - 15 (10+5)
What formula can be used to do this?
Thank you.