Problem:
Consider the arithmetic sequence defined by $a_1=-\frac{19}{12}$, and $a_n=a_{n-1}+4 \sqrt{5}$ for $n > 1$. Compute the nth partial sum, $S_n=\sum_{k=1}^n a_k$, where $n=16$.
Answer:
$8 \left(60 \sqrt{5}-\frac{19}{6}\right)$
{'source': 'AMPS', 'file': 'amps/mathematica/algebra/arithmetic_series/8803.txt'}