Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [3], with each label used at least once.
A220830
Number of unrooted binary leaf-multi-labeled trees with n leaves on the label set [3], with each label used at least once.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =6a(4) =30a(5) =140a(6) =663a(7) =3186a(8) =15642a(9) =78441a(10) =400842a(11) =2084698a(12) =11009358a(13) =58955139a(14) =319619706a(15) =1752122667a(16) =9700923252a(17) =54194387085a(18) =305216395077
External references
- oeis: A220830