职教组卷基于海量职教高考试题库建立的在线组卷及学习系统
职教组卷
  • 题型:填空题 题类:期中考试 难易度:较易

    已知数列\(\{a _{n} \}\),\(\{b _{n} \}\)满足:\(a _{1} =1\),\(a _{n} +a _{n+1} =n\),\(b _{n} =a _{2n-1}\),则数列\(b _{n} =\)______;记\(S _{n}\)为数列\(\{a _{n} \}\)的前\(n\)项和,\(S _{31} -S _{24} =\)______.
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