A334976 - cp's OEIS frontend

A334976 a(n) is the total number of down steps between the (n-1)-th and n-th up steps in all 2-Dyck paths of length 3*n. A 2-Dyck path is a nonnegative path with steps (1, 2), (1, -1) that starts and ends at y = 0.

n	a(n)
0	0
1	0
2	3
3	19
4	108
5	609
6	3468
7	20007
8	116886
9	690690
10	4122495
11	24823188
12	150629248
13	920274804
14	5656456104
15	34954487967
16	217044280458
17	1353539406660
18	8474029162305
19	53241343026795
20	335592121524660
21	2121577490385885
22	13448859209014320
23	85467026778421860

[0, 0, 3, 19, 108, 609, 3468, 20007, 116886, 690690, 4122495, 24823188, 150629248, 920274804, 5656456104, 34954487967, 217044280458, 1353539406660, 8474029162305, 53241343026795, 335592121524660, 2121577490385885, 13448859209014320, 85467026778421860]

cp's OEIS Frontend

A334976 a(n) is the total number of down steps between the (n-1)-th and n-th up steps in all 2-Dyck paths of length 3*n. A 2-Dyck path is a nonnegative path with steps (1, 2), (1, -1) that starts and ends at y = 0.

Table of values

List of values