A114495 - cp's OEIS frontend

A114495 Number of returns to the x-axis in all hill-free Dyck paths of semilength n (a Dyck path is said to be hill-free if it has no peaks at level 1).

n	a(n)
1	0
2	1
3	2
4	7
5	22
6	73
7	246
8	844
9	2936
10	10334
11	36736
12	131709
13	475714
14	1729345
15	6322534
16	23232616
17	85757008
18	317839438
19	1182341740
20	4412949358
21	16521076012
22	62024023306
23	233451103612
24	880764587512
25	3330234867792
26	12617475113968

[0, 1, 2, 7, 22, 73, 246, 844, 2936, 10334, 36736, 131709, 475714, 1729345, 6322534, 23232616, 85757008, 317839438, 1182341740, 4412949358, 16521076012, 62024023306, 233451103612, 880764587512, 3330234867792, 12617475113968]

cp's OEIS Frontend

A114495 Number of returns to the x-axis in all hill-free Dyck paths of semilength n (a Dyck path is said to be hill-free if it has no peaks at level 1).

Table of values

List of values