数列{an}满足a1=1,a2=2,a(n+2)=a(n+1)+2an,则该数列的通项an等于多少?

2025-01-02 11:24:26
推荐回答(1个)
回答1:

两端减2a(n+1)
a(n+2)-2a(n+1) = - (a(n+1)-2an)=
.......= a2-2a1=0
则a(n+2)=2a(n+1)
an=2^(n-1)