(超级容易题目)对于数列an,a1=3,a(n+1)=2an+1,求an
问题描述:
(超级容易题目)对于数列an,a1=3,a(n+1)=2an+1,求an
答
a(n+1)+1=2(an+1)
[a(n+1)+1]/(an+1)=2
{an+1}是首项为a1+1=4,公比为2的等比数列
an+1=4*2^(n-1)=2^(n+1)
an=2^(n+1)-1