AutoFill – Automatically create Serial Number list
Instead of entering data manually on a worksheet, you can use the Auto Fill feature to fill cells with data that follows a pattern or that is based on data in other cells. This article does not explain how to enter data manually or enter data simultaneously on multiple worksheets. For information about how to manually enter data, see the article Enter data manually.
Automatically repeat values that already exist in the column
Using the fill handle, you can quickly fill cells in a range with a series of numbers. Fill in a series of numbers