等差数列{an}和等比数列{bn}满足:a1=b1=1,a2=b2≠1,a5=b
题型:解答题
问题:
等差数列{an}和等比数列{bn}满足:a1=b1=1,a2=b2≠1,a5=b3,设cn=an•bn,其中n∈N*.
(1)求数列{cn}的通项公式;
(2)设Sn=c1+c2+…+cn,求Sn.
等差数列{an}和等比数列{bn}满足:a1=b1=1,a2=b2≠1,a5=b3,设cn=an•bn,其中n∈N*.
(1)求数列{cn}的通项公式;
(2)设Sn=c1+c2+…+cn,求Sn.