a1=8, a(n+1) = an*an/2-4
let an=2*bn
b1=4, b(n+1) = bn*bn-2
let bn=cn+1/cn
c(n+1)+1/c(n+1) = cn*cn+1/cn/cn
c(n) = c(1)^2^(n-1)             这一步是怎么出来的呢？


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修改:zhangzt FROM 36.148.38.*
FROM 36.148.38.*