Exponentiation of g.f. for rooted trees.

Terms

a(0) =1a(1) =2a(2) =6a(3) =22a(4) =95a(5) =470a(6) =2618a(7) =16159a(8) =109177a(9) =799959a(10) =6309111a(11) =53230208a(12) =477941835a(13) =4546562149a(14) =45646689381a(15) =482052312792