1958 AHSME Problem 37

The first term of an arithmetic series of consecutive integers is k^2 + 1. The sum of 2k + 1 terms of this series may be expressed as:

\begin{array}{l} \textbf{(A)}\ k^3 + (k + 1)^3\qquad \textbf{(B)}\ (k - 1)^3 + k^3\qquad \textbf{(C)}\ (k + 1)^3\qquad \\ \textbf{(D)}\ (k + 1)^2\qquad \textbf{(E)}\ (2k + 1)(k + 1)^2 \end{array}

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.