By Induction prove

Recall

I know proof by induction is something to do with putting a +1 by the n's however i am fairly clueless as to this example. Thanks.

ps: the dots between 1.3.5 represent multiplying 1 3 and 5. and the dots after are meant to symbolise a series continuing. i'm also a bit confused as to what that series is... 1, 3, 5 perhaps it's just a difference of two each time?