Proof Writing & Problem Solving · Easy problem

To prove "if $n = 5k + 2$ then $5 \mid n^2 + 1$", expand: $n^2 + 1 = 25k^2 + 20k + 5 = 5(5k^2 + 4k + 1)$. For $n = 17$, what is $5k^2 + 4k + 1$?