Number of boron trees with n nodes, i.e. n-node rooted trees with degree <= 3 at root and out-degree <= 2 elsewhere.
A000671
Number of boron trees with n nodes, i.e. n-node rooted trees with degree <= 3 at root and out-degree <= 2 elsewhere.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =2a(4) =4a(5) =7a(6) =14a(7) =29a(8) =60a(9) =127a(10) =275a(11) =598a(12) =1320a(13) =2936a(14) =6584a(15) =14858a(16) =33744a(17) =76999a(18) =176557a(19) =406456a(20) =939241a(21) =2177573a(22) =5064150a(23) =11809632a(24) =27610937a(25) =64705623a(26) =151966597a(27) =357623905a(28) =843176524a(29) =1991439229
External references
- oeis: A000671