Formula for data validation for entry series number only

Originally Posted by shivya

1. Enter 1000 in A1
2. select A2
3. Go to Data Validation
4. Select Whole number
5. In formula, type =A1+1
6. Copy validation and paste in other cells as well by selecting validation in paste special.

Uncheck "ignore blank"

Now. User will not be able to leave any cell blank