A334786 - cp's OEIS frontend

A334786 a(n) is the total number of down steps before the first up step in all 4_2-Dyck paths of length 5*n. A 4_2-Dyck path is a lattice path with steps (1, 4), (1, -1) that starts and ends at y = 0 and stays above the line y = -2.

n	a(n)
0	0
1	3
2	16
3	115
4	950
5	8510
6	80388
7	788392
8	7950930
9	81935425
10	859005840
11	9132977490
12	98240702586
13	1067197649840
14	11691092372000
15	129011823098160
16	1432744619523530
17	16000911127589355
18	179590878292003200
19	2024687100104286525
20	22917687021180660940

[0, 3, 16, 115, 950, 8510, 80388, 788392, 7950930, 81935425, 859005840, 9132977490, 98240702586, 1067197649840, 11691092372000, 129011823098160, 1432744619523530, 16000911127589355, 179590878292003200, 2024687100104286525, 22917687021180660940]

cp's OEIS Frontend

A334786 a(n) is the total number of down steps before the first up step in all 4_2-Dyck paths of length 5*n. A 4_2-Dyck path is a lattice path with steps (1, 4), (1, -1) that starts and ends at y = 0 and stays above the line y = -2.

Table of values

List of values