已知Sm,Sn分別表示等差數列{an}的前m項與前n項的和,且SmSn=m2n2,那麼aman=______.

已知Sm,Sn分別表示等差數列{an}的前m項與前n項的和,且SmSn=m2n2,那麼aman=______.

在等差數列中,∵SmSn=m2n2,∴aman=2am2an=a1+a2m−1a1+a2n−1=a1+a2m−12a1+a2n−12=a1+a2m−12×(2m−1)a1+a2n−12×(2n−1)×2n−12m−1=S2m−1S2n−1×2n−12m−1=(2m−1)2(2n−1)2×2n−12m−1=2m−12n−1,故答案為:2m−12n−1