a(n+1)=an/(2an+1)2a(n+1)an+a(n+1)-an=0两边同除以a(n+1)an得2+1/an-1/a(n+1)=01/a(n+1)-1/an=2令bn=1/anb1=1/a1=1数列{bn}为首项是1,公差是2的等差数列.bn=1/an=1+2(n-1)=2n-1所以an=1/(2n-1)...