APEX

I would like to display the row number in the report region at the beginning of each row for each page (based on the number of rows to display per page).
So if the number of rows per page is 15, I would want to show each row from 1 to 15. When going to the next page (16 - 31) I would like to show row 1 to 15 again next to each row.
And if the number of rows per page is 20, I want to see row numbers 1 to 20 on each page.

Since I believe an Update button only processes the current page, I would like to then use this row numbers (1 - 15) to get the values of the displayed column for each row to perform an insert to another table.