A120985 - cp's OEIS frontend

A120985 Number of ternary trees with n edges and having no vertices of degree 2. 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.

n	a(n)
0	1
1	3
2	9
3	28
4	93
5	333
6	1272
7	5085
8	20925
9	87735
10	372879
11	1602450
12	6953824
13	30438138
14	134255403
15	596154495
16	2662813341
17	11955684591
18	53927330037
19	244250703252
20	1110401393067
21	5065143385647
22	23176155530394
23	106344639962973

[1, 3, 9, 28, 93, 333, 1272, 5085, 20925, 87735, 372879, 1602450, 6953824, 30438138, 134255403, 596154495, 2662813341, 11955684591, 53927330037, 244250703252, 1110401393067, 5065143385647, 23176155530394, 106344639962973]

cp's OEIS Frontend

A120985 Number of ternary trees with n edges and having no vertices of degree 2. 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.

Table of values

List of values