I wrote: > I looked at these two sequences counting the aggregate number of leaves > in rooted trees and trees. > > ID Number: A003227 (Formerly M2744) ... > ID Number: A003228 (Formerly M0351) ... > My calculations agree with those above for n=1 to 21, but for n=22 ... I contacted Bob Robinson. He recalculated the values and discovered that mine were correct. So this issue is settled. Christian