What is the value of limn→∞∑k=1narctan(1k2+3k+3)\lim_{n \to \infty} \sum_{k=1}^n \arctan(\frac{1}{k^2 + 3k + 3})limn→∞∑k=1narctan(k2+3k+31)?
arctan(1)\arctan(1)arctan(1)
arctan(2)\arctan(2)arctan(2)
arctan(1/3)\arctan(1/3)arctan(1/3)
arctan(1/2)\arctan(1/2)arctan(1/2)