Mac Forum / Applications / Excel / November 2006

One way:

Enter 1 in the top cell. While holding the CTRL-key, click and hold the
"fill handle"  (lower right corner of the cell) and drag down. Choose
Fill Series from the pop-up menu.

another:

Enter 1 in the top cell and 2 below it. Select the two cells. Click and
hold the fill handle of the bottom cell and drag down.

and another:

Enter 1 in the top cell (say, cell A1). In the cell below it, enter

   =A1 + 1

Select the second cell, copy down as far as desired.

yet another:

Enter 1 in the top cell. Select the range you want to fill. Choose
Edit/Fill/Series..., click OK.

And here is 6th.; write "1" hit enter, write "2" hit enter, write "3"
hit enter... etc. :P