Excel Auto Fill Columns with Numeric Value

Fill a column with a series of numbers

1. Select the first cell in the range that you want to fill.
2. Type the starting value for the series.
3. Type a value in the next cell to establish a pattern. …
4. Select the cells that contain the starting values. …
5. Drag the fill handle.

Sources:

https://support.microsoft.com/en-us/office/automatically-number-rows-76ce49e3-d8d2-459b-bd85-ee1d3973e6e6