No 6 (Grange) and 7 (Donnybrook) from when I used to get them years ago.
Though I think all buses are now "206" and "207"
Get off by the Garage by the Tesco's and walk over - go for an hour before the first day and then you can get the next one etc untill you get the right one
Price "was" 1.60 ... probably higher now.
Fares have also one up by 10cent, so all single adult tickets will be €1.70!
1 minute work on Google