A355281 - cp's OEIS frontend

A355281 Number of pairs of nested Dyck paths from (0,0) to (n,n) such that the upper path only touches the diagonal at its endpoints.

n	a(n)
0	1
1	1
2	2
3	9
4	55
5	400
6	3266
7	28999
8	274537
9	2734885
10	28401315
11	305352146
12	3380956839
13	38394091370
14	445702108969
15	5274935433915
16	63507021523471
17	776347636736261
18	9621502184089320
19	120726786082609207
20	1531938384684090884
21	19639252409244653785
22	254143269904958943103
23	3317204158078663935592

[1, 1, 2, 9, 55, 400, 3266, 28999, 274537, 2734885, 28401315, 305352146, 3380956839, 38394091370, 445702108969, 5274935433915, 63507021523471, 776347636736261, 9621502184089320, 120726786082609207, 1531938384684090884, 19639252409244653785, 254143269904958943103, 3317204158078663935592]

cp's OEIS Frontend

A355281 Number of pairs of nested Dyck paths from (0,0) to (n,n) such that the upper path only touches the diagonal at its endpoints.

Table of values

List of values