数列\(\left\{ {{a}_{n}} \right\}\)满足\({{a}_{1}}{=}1\),\(n{{a}_{n+1}}{=}\left( n+1 \right){{a}_{n}}+n\left( n+1 \right)\),且\({{b}_{n}}{=}{{a}_{n}}\cos \dfrac{2n\pi }{3}\),记\({{S}_{n}}\)为数列\(\left\{ {{b}_{n}} \right\}\)的前\(n\)项和,则\({{S}_{120}}=\)_______.