已知首项都是\(1\)的数列\(\{a _{n} \}\)，\(\{b _{n} \}(b _{n} \neq 0 , n∈N ^{*} )\)满足\(a _{n} b _{n+1} -a _{n+1} b _{n} +2b _{n} b _{n+1} =0\)
\((I)\)令\(c _{n} = \dfrac {a_{n}}{b_{n}}\)，求数列\(\{c _{n} \}\)的通项公式；
\((\)Ⅱ\()\)令数列\(b _{n} =3 ^{n+1}\)，求数列\(\{a _{n} \}\)的前\(n\)项和\(S _{n}\)．
