How to copy value from every nth column with INDEX function?

[Jermine]

Hi guys, I need a help in solving the below problem.

I would like to return the cell value from every 3rd column, but having an issue with OFFSET function as it does not work with a closed workbook.
Knowing that INDEX function would be an alternative, but I have no idea with it, can someone share an example with me pls?

For an example, I wanna copy I4, L4 O4 U4 and so on, which is every 3rd column from the previous selection.

 

[jasonb75]

Assuming that the formula is going into consecutive columns, something like this.

=INDEX($I$4:$U$12,1,INT((COLUMNS($A2:A2)-1)*3+1))

The reference to A$2:A2 should be changed to the first cell that the formula is going into so that it doesn't error if rows / columns are inserted or deleted.

 

[kbasco2000]

You are the best!
So simple answer, it works in google sheets too.
Thank you!!!