Answer
It does not make any sense.
Work Step by Step
The given expression is: ${{a}_{1}}^{{}},{{a}_{2}}^{{}},{{a}_{3}}^{{}},{{a}_{4}}^{{}}\ldots,{{a}_{n}}\ldots $
So, ${{a}_{1}}$ could be anything either positive or negative. Similarly, to ${{a}_{1}}^{{}},{{a}_{2}}^{{}},{{a}_{3}}^{{}},{{a}_{4}}^{{}}\ldots,{{a}_{n}}\ldots $
The sequence is the set of positive integers which is dependent on the expression of ${{a}_{1}}^{{}},{{a}_{2}}^{{}},{{a}_{3}}^{{}},{{a}_{4}}^{{}}\ldots,{{a}_{n}}\ldots $
Therefore if ${{a}_{n}}=3{{n}^{2}}-{{n}^{3}}$
The first 2 terms are positive and the 3rd term is 0; after 4th term, all terms are negative.
$\begin{align}
& {{a}_{1}}=3{{\left( 1 \right)}^{2}}-{{\left( 1 \right)}^{3}}=2 \\
& {{a}_{2}}=3{{\left( 2 \right)}^{2}}-{{\left( 2 \right)}^{3}}=4 \\
& {{a}_{3}}=3{{\left( 3 \right)}^{2}}-{{\left( 3 \right)}^{3}}=0 \\
& {{a}_{4}}=3{{\left( 4 \right)}^{2}}-{{\left( 4 \right)}^{3}}=-16 \\
& {{a}_{5}}=3{{\left( 5 \right)}^{2}}-{{\left( 5 \right)}^{3}}=-50 \\
\end{align}$
