Powers of rooted tree enumerator.

Terms

a(0) =9a(1) =30a(2) =69a(3) =133a(4) =230a(5) =369a(6) =560a(7) =814a(8) =1143a(9) =1560a(10) =2079a(11) =2715a(12) =3484a(13) =4403a(14) =5490a(15) =6764a(16) =8245a(17) =9954a(18) =11913a(19) =14145a(20) =16674a(21) =19525a(22) =22724a(23) =26298a(24) =30275a(25) =34684a(26) =39555a(27) =44919a(28) =50808a(29) =57255