有關an1an2n1的精選大全

已知數列{an}滿足an+1=an+2n+1,a1=1,則a5=    .
問題詳情:已知數列{an}滿足an+1=an+2n+1,a1=1,則a5=  .【回答】25.【考點】8H:數列遞推式.【分析】an+1=an+2n+1,可得an﹣an﹣1=2(n﹣1)+1.(n≥2).利用累加求和實數即可得出.【解答】解:∵an+1=an+2n+1,∴an﹣an﹣1=2(n﹣1)+1.(n≥2).∴an=(an﹣an﹣1)+(an﹣1﹣an﹣2...
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