Update.
In cell R1, I entered Week 1.
In cell S1 I entered =LEFT(R1,5)&RIGHT(R1,1)+1.
I then copied the formula in cell S1 and pasted it into cells T1 and U1.
The end result was that in Cell R1 thru Cell U1 I got Week 1, Week 2, Week 3 and Week 4.
Thanks to everyone for your help.