纠结!数列{an}中,a1=1,an+1=2an,求a2^2+a4^2+a6^2+……+a2n^21/4*16*(1-16^n)/(1-16)=4/15 * (16^n-1)

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纠结!数列{an}中,a1=1,an+1=2an,求a2^2+a4^2+a6^2+……+a2n^21/4*16*(1-16^n)/(1-16)=4/15*(16^n-1)纠结!数列{an}中,a1=1

纠结!数列{an}中,a1=1,an+1=2an,求a2^2+a4^2+a6^2+……+a2n^21/4*16*(1-16^n)/(1-16)=4/15 * (16^n-1)
纠结!数列{an}中,a1=1,an+1=2an,求a2^2+a4^2+a6^2+……+a2n^2
1/4*16*(1-16^n)/(1-16)
=4/15 * (16^n-1)

纠结!数列{an}中,a1=1,an+1=2an,求a2^2+a4^2+a6^2+……+a2n^21/4*16*(1-16^n)/(1-16)=4/15 * (16^n-1)
an=2^(n-1)
so a2n^2=2^(4n-2)=4^(2n-1)=1/4*16^n
a2^2+a4^2+a6^2+……+a2n^2
=1/4*16*(1-16^n)/(1-16)
=4/15 * (16^n-1)