已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1若an为等比数列,求bn的前n项和Sn

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已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1若an为等比数列,求bn的前n项和Sn已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1若an为等比数

已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1若an为等比数列,求bn的前n项和Sn
已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1
若an为等比数列,求bn的前n项和Sn

已知数列an满足:a1=1,a2=a(a大于0),数列bn=an×an+1若an为等比数列,求bn的前n项和Sn
通式an=a^(n-1)
则bn=a^(2n-1) +1
bn的前n项和Sn=n+a^1+a^3+a^5+…a^(2n-1)
=n+a(1-a^2n)/(1-a^2)

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