A127156 - cp's OEIS frontend

A127156 Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n starting with exactly k consecutive pyramids. A pyramid in a Dyck path is a factor of the form U^j D^j (j>0), starting at the x-axis. Here U=(1,1) and D=(1,-1). This definition differs from the one in A091866.

n	a(n)
0	1
1	0
2	1
3	0
4	1
5	1
6	1
7	1
8	2
9	1
10	5
11	2
12	3
13	3
14	1
15	19
16	7
17	5
18	6
19	4
20	1
21	67
22	26
23	12
24	11
25	10
26	5
27	1
28	232
29	93
30	38
31	23
32	21
33	15
34	6
35	1
36	804
37	325
38	131
39	61
40	44
41	36
42	21
43	7
44	1
45	2806
46	1129
47	456
48	192
49	105
50	80
51	57
52	28
53	8
54	1
55	9878
56	3935
57	1585
58	648
59	297
60	185
61	137
62	85
63	36
64	9
65	1
66	35072
67	13813
68	5520

[1, 0, 1, 0, 1, 1, 1, 1, 2, 1, 5, 2, 3, 3, 1, 19, 7, 5, 6, 4, 1, 67, 26, 12, 11, 10, 5, 1, 232, 93, 38, 23, 21, 15, 6, 1, 804, 325, 131, 61, 44, 36, 21, 7, 1, 2806, 1129, 456, 192, 105, 80, 57, 28, 8, 1, 9878, 3935, 1585, 648, 297, 185, 137, 85, 36, 9, 1, 35072, 13813, 5520]

cp's OEIS Frontend

A127156 Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n starting with exactly k consecutive pyramids. A pyramid in a Dyck path is a factor of the form U^j D^j (j>0), starting at the x-axis. Here U=(1,1) and D=(1,-1). This definition differs from the one in A091866.

Table of values

List of values