A108426 - cp's OEIS frontend

A108426 Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k peaks of the form Ud.

n	a(n)
0	1
1	1
2	1
3	3
4	5
5	2
6	12
7	28
8	21
9	5
10	55
11	165
12	180
13	84
14	14
15	273
16	1001
17	1430
18	990
19	330
20	42
21	1428
22	6188
23	10920
24	10010
25	5005
26	1287
27	132
28	7752
29	38760
30	81396
31	92820
32	61880
33	24024
34	5005
35	429
36	43263
37	245157
38	596904
39	813960
40	678300
41	352716
42	111384
43	19448
44	1430
45	246675

[1, 1, 1, 3, 5, 2, 12, 28, 21, 5, 55, 165, 180, 84, 14, 273, 1001, 1430, 990, 330, 42, 1428, 6188, 10920, 10010, 5005, 1287, 132, 7752, 38760, 81396, 92820, 61880, 24024, 5005, 429, 43263, 245157, 596904, 813960, 678300, 352716, 111384, 19448, 1430, 246675]

cp's OEIS Frontend

A108426 Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k peaks of the form Ud.

Table of values

List of values