Sna11anan13的精选

问题详情：数列{an}的前n项和为Sn,a1=1,an+an+1=3×2n-1,则S2017=()A.22018-1         B.22018+1      C.22017-1         D.22017+1【回答】C由a1=1和an+1=3×2n-1-an,可知数列{an}唯一确定,...