This should be so easy, don't know what I'm missing.

Excel 2003-
I have a list of numbers that I need to go

2
3
4
5
6
7
8
11
12
13
14
15
16
17
20
21
22
....

so basically, it's increment of one for seven rows, then it increments by three.

I tried selecting the first two sets of series and then doing fill handle, but that did not work at all. I got weird numbers from it doing some sort of calculation.

Please help!