存在:λ的值为1/2或4
a(n+1)=4an-3n+1
a(n+1)-(n+1)=4(an-n)
[a(n+1)-(n+1)]/(an-n)=4
{an-n}为等比数列,公比为:4,首项为:1
an-n=4^(n-1)
an=4^(n-1)+n
sn=[4^n-1]/3+[1+n]n/2
存在:λ的值为1/2或4
a(n+1)=4an-3n+1
a(n+1)-(n+1)=4(an-n)
[a(n+1)-(n+1)]/(an-n)=4
{an-n}为等比数列,公比为:4,首项为:1
an-n=4^(n-1)
an=4^(n-1)+n
sn=[4^n-1]/3+[1+n]n/2