Write out explicitly what is meant by $\displaystyle \sum_{k=1}^{4}(2k+1)^2$

I'm not used to have something like 2k+1 after it, its usually asked differently. Please help.

$\displaystyle \sum_{k=1}^{4}(2k+1)^2$ means $\displaystyle (2(1)+1)^2 + (2(2)+1)^2+(2(3)+1)^2+(2(4)+1)^2$ ,i.e, the sum of this series with index k starting from 1 to 4