Triangle read by rows: T(n,k) is the number of ternary trees with n edges and having k leaves (i.e., vertices of degree 0; n>=0, k>=1). A ternary tree is a rooted tree in which each vertex has at most three children and each child of a vertex is designated as its left or middle or right child.
A120429
Triangle read by rows: T(n,k) is the number of ternary trees with n edges and having k leaves (i.e., vertices of degree 0; n>=0, k>=1). A ternary tree is a rooted tree in which each vertex has at most three children and each child of a vertex is designated as its left or middle or right child.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =3a(4) =27a(5) =27a(6) =1a(7) =81a(8) =162a(9) =30a(10) =243a(11) =810a(12) =360a(13) =15a(14) =729a(15) =3645a(16) =2970a(17) =405a(18) =3a(19) =2187a(20) =15309a(21) =19845a(22) =5670a(23) =252a(24) =6561a(25) =61236a(26) =115668a(27) =56700a(28) =6426a(29) =84
External references
- oeis: A120429