Suppose that a sequence of numbers an>0 has the property that a1=1 and an+1=(n+1)21Sn, where Sn=a1+⋯+an. Can you determine whether ∑n=1∞an converges? (Hint: S2=a2+a1=a2+S1=a2+1=1+1/4=(1+1/4)S1, S3=321S2+S2=(1+1/9)S2=(1+1/9)(1+1/4)S1, etc. Look at ln(Sn), and use ln(1+t)≤t, t>0.)