数列这个怎么答,如图,数列

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数列这个怎么答,如图,数列
数列这个怎么答,如图,数列
 

数列这个怎么答,如图,数列
s(n)+1 = [a(1)+1]2^(n-1),
s(n+1) + 1 = [a(1)+1]2^n,
a(n+1) = s(n+1)+1 - [ s(n)+1] = [a(1)+1]2^n - [a(1)+1]2^(n-1) = [a(1)+1]2^(n-1).
a(2) = [a(1)+1],
a(3) = [a(1)+1]*2
[a(2)]^2 = [a(1)+1]^2 = a(1)a(3) = a(1)[a(1)+1]*2,
a(1)+1 = 2a(1),
a(1) = 1.
a(n+1) = [a(1)+1]2^(n-1) = 2*2^(n-1) = 2^n,
a(n) = 2^(n-1).