Number of asymmetric mobiles (circular rooted trees) with n nodes and 3 leaves.

Terms

a(0) =1a(1) =4a(2) =10a(3) =22a(4) =42a(5) =73a(6) =119a(7) =184a(8) =272a(9) =389a(10) =540a(11) =731a(12) =969a(13) =1261a(14) =1614a(15) =2037a(16) =2538a(17) =3126a(18) =3811a(19) =4603a(20) =5512a(21) =6550a(22) =7728a(23) =9058a(24) =10553a(25) =12226a(26) =14090a(27) =16160a(28) =18450a(29) =20975