A108438 - cp's OEIS frontend

A108438 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 having abscissa of the first peak equal to k.

n	a(n)
1	1
2	1
3	4
4	3
5	2
6	1
7	24
8	18
9	13
10	7
11	3
12	1
13	172
14	130
15	96
16	55
17	28
18	12
19	4
20	1
21	1360
22	1034
23	772
24	458
25	249
26	119
27	50
28	18
29	5
30	1
31	11444
32	8738
33	6568
34	3982
35	2244
36	1137
37	526
38	219
39	80
40	25
41	6
42	1
43	100520
44	76994
45	58140
46	35770
47	20624
48	10836
49	5293
50	2383
51	981
52	365
53	119
54	33
55	7
56	1

[1, 1, 4, 3, 2, 1, 24, 18, 13, 7, 3, 1, 172, 130, 96, 55, 28, 12, 4, 1, 1360, 1034, 772, 458, 249, 119, 50, 18, 5, 1, 11444, 8738, 6568, 3982, 2244, 1137, 526, 219, 80, 25, 6, 1, 100520, 76994, 58140, 35770, 20624, 10836, 5293, 2383, 981, 365, 119, 33, 7, 1]

cp's OEIS Frontend

A108438 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 having abscissa of the first peak equal to k.

Table of values

List of values