A033296 - cp's OEIS frontend

A033296 Number of paths from (0,0) to (3n,0) that stay in first quadrant (but may touch horizontal axis), where each step is (2,1),(1,2) or (1,-1) and start with (1,2).

n	a(n)
0	1
1	1
2	6
3	42
4	326
5	2706
6	23526
7	211546
8	1951494
9	18366882
10	175674054
11	1702686090
12	16686795846
13	165079509042
14	1646340228006
15	16534463822010
16	167081444125702
17	1697551974416706
18	17330661859937670
19	177699201786231530

[1, 1, 6, 42, 326, 2706, 23526, 211546, 1951494, 18366882, 175674054, 1702686090, 16686795846, 165079509042, 1646340228006, 16534463822010, 167081444125702, 1697551974416706, 17330661859937670, 177699201786231530]

cp's OEIS Frontend

A033296 Number of paths from (0,0) to (3n,0) that stay in first quadrant (but may touch horizontal axis), where each step is (2,1),(1,2) or (1,-1) and start with (1,2).

Table of values

List of values