Count up to a number, then back down to 1, then back up

Is there some sort of formula I could put together to do this?

Like for example, if I wanted a column to read
1
2
3
4
4
3
2
1
1
2
3
4

Without putting in those numbers manually, how could I do that?

Put this in your starting cell (doesn't have to be A1 - it can be anywhere):

=IF(MOD(INT((ROWS($1:1)-1)/4),2)=0,MOD(ROWS($1:1)-1,4)+1,4-MOD(ROWS($1:1)-1,4))

and then copy down.

Hope this helps.

Pete