Question

关于数列的问题等差数列｛an｝中,首项a1=1,公差d≠0,前n项和为Sn,已知数列ak1,ak2,ak3,ak,……a

Answer 1

d=2,an=2n-1,akn=3^(n-1)=2kn-1,kn=(3^(n-1)+1)/2