A001558 - cp's OEIS frontend

A001558 Number of hill-free Dyck paths of semilength n+3 and having length of first descent equal to 1 (a hill in a Dyck path is a peak at level 1).

n	a(n)
0	1
1	3
2	10
3	33
4	111
5	379
6	1312
7	4596
8	16266
9	58082
10	209010
11	757259
12	2760123
13	10114131
14	37239072
15	137698584
16	511140558
17	1904038986
18	7115422212
19	26668376994
20	100221202998
21	377570383518
22	1425706128480
23	5394898197448
24	20454676622476

[1, 3, 10, 33, 111, 379, 1312, 4596, 16266, 58082, 209010, 757259, 2760123, 10114131, 37239072, 137698584, 511140558, 1904038986, 7115422212, 26668376994, 100221202998, 377570383518, 1425706128480, 5394898197448, 20454676622476]

cp's OEIS Frontend

A001558 Number of hill-free Dyck paths of semilength n+3 and having length of first descent equal to 1 (a hill in a Dyck path is a peak at level 1).

Table of values

List of values