How to prove [1+5+9+13+...+(4n1)] = (n+1)(2n+1) by induction?

How to prove [1+5+9+13+...+(4n1)] = (n+1)(2n+1) by induction?
Update: It was 4n+1. That's weird, it was 4n+1? Anyways, I got help. Thanks!
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