Synth part, the whole song goes like this.

e|-----------13------------15~---13~---18~---------13~-------------| (13)
B|-15~----------15~---------------------------13~-------15~--------|
G|------12~---------15~--------------------------------------------|
D|-----------------------------------------------------------15~---|
A|-----------------------------------------------------------------|
E|-----------------------------------------------------------------|

the (13) at the end is only played if the riff repeats.