Solve for S_n
S_{n}=\frac{n\left(n+1\right)\left(2n+1\right)}{6}
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S_{n}=\frac{1}{3}n^{3}+\frac{1}{2}n^{2}+\frac{1}{6}n
Use the distributive property to multiply \frac{1}{6}n by 2n^{2}+3n+1.
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