Multi Sheet formula auto-populate?

I have tallied some totals from several sheets to show a standings on each of those sheets. But the formula references sheets that doesn't exist yet and it doesn't work. because of that I had to create extra weeks down the road for the formula to work. It is for the baseball season and each sheet represents a week so I have to create about 20+ weeks. No big deal. But now I am trying to write out the formula and I am wondering if there is an easier way than typing out this formula for all these weeks. I manually typed it for the first few weeks but it is a pain in the but and I am wondering if I have to write the whole thing out for 20 some odd weeks.

=SUM('Week 1'!R9,'WEEK 2'!R9,'WEEK 3'!R9,'WEEK 4'!R9,'WEEK 5'!R9)

This is the formula I am using. Do I have to write it out for all the weeks? or is there an easier way to do this whole standings thing that I am hoping to add to each sheet (week).

I have attached the whole sheet for your viewing pleasure.

Thanks for any suggestions.