题目

Teaching is more than leadership. Some of the teacher’s time and effort is directed toward instruction, some toward evaluation. But it is the teacher as a group leader who creates an effective organizational structure and good working environment so that instruction and evaluation activities can take place. A group that is totally disorganized, unclear about its goals, or constantly fighting among its members will not be a good learning group. The leadership pattern includes helping to form and maintain a positive learning environment so that instruction and evaluation activities c数列{an}的前n项和为Sn=n2，数列{bn}满足b1=1，且bn=2bn-1+1，n≥2．（1）求an，bn的表达式；（2）设cn=an•bn，求数列{cn}的前n项和Tn．