We can do this by substituting $n=1,2,3,4,5$ into the formula $a_{n}=\frac{3(-1)^{n}}{n}$.
For $n=1$, we get $a_{1}=\frac{3(-1)^{1}}{1}=-3$.
For $n=2$, we get $a_{2}=\frac{3(-1)^{2}}{2}=\frac{3}{2}$.
For $n=3$, we get $a_{3}=\frac{3(-1)^{3}}{3}=-1$.
For $n=4$,
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