Here is a quick way to create a column of sequential numbers:
Type "1" in cell A1 and the formula "=A1+1" in cell A2 (both without the quotes). Then select cells A2 thru A10 (or whatever) and choose Fill Down from the Calculate menu (or type Command-D).
Creating a column of numbers followed by a period is tricky. Simply typing "1." will result in that cell being interpreted as a number (1.0) which equals 1, therefore the decimal is automatically stripped away.
To avoid this, type the following into cell A1(with the quotes): ="1."
Then type this formula (again, with the quotes) into cell A2: =A1+1&"."
Select cells A2 thru A10 and choose Fill Down.
Explanation:
The value of cell A1 is: 1. but the numeric value is 1. Because cell A2 is performing arithmetic functions, it takes the numeric value of cell A1 and adds 1 to it, resulting in 2. This result is then concatenated (combined) with the period.