5.
已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(a_{1}=1\),且\(S_{n+1}= \dfrac {n+1}{n}S_{n}+ \dfrac {n+1}{2}(n∈N*)\)
\((1)\)求数列\(\{a_{n}\}\)的通项公式;
\((2)\)设\(a_{n}=2^{n-1}b_{n}(n∈N*)\),数列\(\{b_{n}\}\)的前\(n\)项和为\(T_{n}\),若\(T_{n}\geqslant k\)对于\(n∈N*\)恒成立,求实数\(k\)的最大值.