等比数列,a1=1/3,a下标n+1=2a下标n,则a下标n=?,a10=?

Question

等比数列,a1=1/3,a下标n+1=2a下标n,则a下标n=?,a10=?

Answer 1

这是首项为1/3,公比为2的等比数列
所以
an=a1*q^(n-1)=1/3·2^(n-1)
a10=1/3·2^(10-1)
=512/3