Basic formula to create a number sequence in Excel. Go to the Page Layout tab. Once we select the arrow at the bottom right corner of the Page Setup area the Page Setup dialog box appears as shown in the image below.
The page numbers will be automatically updated.
Here is how to do this. Left click on your mouse while hovering your cursor over the plus sign. Click Go to Footer button. To enter specific sequential number codes such as purchase order numbers you can use the ROW function together with the TEXT function.