I am creating a weekly budge workbook but I need help with some formulas

I have 52 sheets named Week (1) - Week (52)

I want a running 4 week total on each page

For week (5)

=SUM('Week (1):Week (4)'!C30)

but I don't want to manually go and type for each sheet what I really want is

=SUM('Week (current index number - 4):Week (current index number - 1)'!C30)

Is there a formula to do this.