对于无穷数列\(\{{{a}_{n}}\}\),\(\{{{b}_{n}}\}\),若\({{b}_{k}}=\max \{{{a}_{1}},{{a}_{2}},\cdots ,{{a}_{k}}\}-\min \{{{a}_{1}},{{a}_{2}},\cdots ,{{a}_{k}}\}(k=1,2,3,\cdots )\),则称\(\{{{b}_{n}}\}\)是\(\{{{a}_{n}}\}\)的“收缩数列”\(.\) 其中,\(\max \{{{a}_{1}},{{a}_{2}},\cdots ,{{a}_{k}}\}\),\(\min \{{{a}_{1}},{{a}_{2}},\cdots ,{{a}_{k}}\}\)分别表示\({{a}_{1}},{{a}_{2}},\cdots ,{{a}_{k}}\)中的最大数和最小数.已知\(\{{{a}_{n}}\}\)为无穷数列,其前\(n\)项和为\({{S}_{n}}\),数列\(\{{{b}_{n}}\}\)是\(\{{{a}_{n}}\}\)的“收缩数列”.
\((\)Ⅰ\()\)若\({{a}_{n}}=2n+1\),求\(\{{{b}_{n}}\}\)的前\(n\)项和;
\((\)Ⅱ\()\)证明:\(\{{{b}_{n}}\}\)的“收缩数列”仍是\(\{{{b}_{n}}\}\);
\((\)Ⅲ\()\)若\({{S}_{1}}+{{S}_{2}}+\cdots +{{S}_{n}}=\dfrac{n(n+1)}{2}{{a}_{1}}+\dfrac{n(n-1)}{2}{{b}_{n}}(n=1,2,3,\cdots )\),求所有满足该条件的\(\{{{a}_{n}}\}\).