The general term of the sequence $\dfrac{1}{2}, \dfrac{1}{5}, \dfrac{1}{10}, \dfrac{1}{17}, \ldots$ is —

• a$\dfrac{1}{n+1}$
• b$\dfrac{1}{2n}$
• c$\dfrac{1}{n^2 + 1}$
• d$\dfrac{1}{2n - 1}$