A334645 - cp's OEIS frontend

A334645 a(n) is the total number of down steps between the 2nd and 3rd up steps in all 3-Dyck paths of length 4*n. A 3-Dyck path is a nonnegative lattice path with steps (1, 3), (1, -1) that starts and ends at y = 0.

n	a(n)
0	0
1	0
2	18
3	52
4	277
5	1752
6	12120
7	88692
8	674751
9	5282160
10	42267384
11	344152080
12	2842055359
13	23746693240
14	200383750632
15	1705243729560
16	14617677294675
17	126106202849760
18	1094034474058488
19	9538676631305712
20	83536778390997780
21	734521734171474400
22	6481894477750488160

[0, 0, 18, 52, 277, 1752, 12120, 88692, 674751, 5282160, 42267384, 344152080, 2842055359, 23746693240, 200383750632, 1705243729560, 14617677294675, 126106202849760, 1094034474058488, 9538676631305712, 83536778390997780, 734521734171474400, 6481894477750488160]

cp's OEIS Frontend

A334645 a(n) is the total number of down steps between the 2nd and 3rd up steps in all 3-Dyck paths of length 4*n. A 3-Dyck path is a nonnegative lattice path with steps (1, 3), (1, -1) that starts and ends at y = 0.

Table of values

List of values