please help!! I have a column of values, and I want a column next to it that shows the value in every second cell in the first column, but right underneath. See below for an example of what I am trying to achieve. The actual column is 17000 cells so I cant do it manually. please can someone help me. thank you,

1 2
2 4
3 6
4 8
5 10
6 12
7
8
9
10