A128720 - cp's OEIS frontend

A128720 Number of paths in the first quadrant from (0,0) to (n,0) using steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0).

n	a(n)
0	1
1	1
2	3
3	6
4	16
5	40
6	109
7	297
8	836
9	2377
10	6869
11	20042
12	59071
13	175453
14	524881
15	1579752
16	4780656
17	14536878
18	44394980
19	136107872
20	418757483
21	1292505121
22	4001039563
23	12418772656
24	38641790001
25	120510911885
26	376628460529
27	1179376013552
28	3699860515924
29	11626784875214

[1, 1, 3, 6, 16, 40, 109, 297, 836, 2377, 6869, 20042, 59071, 175453, 524881, 1579752, 4780656, 14536878, 44394980, 136107872, 418757483, 1292505121, 4001039563, 12418772656, 38641790001, 120510911885, 376628460529, 1179376013552, 3699860515924, 11626784875214]

cp's OEIS Frontend

A128720 Number of paths in the first quadrant from (0,0) to (n,0) using steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0).

Table of values

List of values