Greg_Deckler 

v-kelly-msft 

Thank you both for your times.

I had someone point me at the direction of the List.Generate. 

But was about the same time I discover how to do the loop with function and about recursive function.

From what I understand  my problem can be solved in both ways :  

1) Using List.Generate

2) Using recursive function 

Do you agree? Or do I have to combine both?

I had already watched that video, but I found it a little bit complicated ( the function itself is ).. and since I was already involved in the second method I decided to try a little bit more this way, before starting all over.

I will keep trying this next few days. Gona read again all the previous messages and see if I can make it work.

I was reading the documentation and found this explanation that maybe can help me with the solution:

"

List and record member expressions (as well as let expressions, introduced further below) are evaluated using lazy evaluation, which means that they are evaluated only as needed. All other expressions are evaluated using eager evaluation, which means that they are evaluated immediately when encountered during the evaluation process. A good way to think about this is to remember that evaluating a list or record expression will return a list or record value that itself remembers how its list items or record fields need to be computed, when requested (by lookup or index operators). "

Again, thank you all for the help!