A240904 - cp's OEIS frontend

A240904 Number of lattice paths from (0,0) to (n,0) that do not go below the x-axis or above the diagonal x=y and consist of steps u=(1,1), U=(1,3), H=(1,0), d=(1,-1) and D=(1,-3).

n	a(n)
0	1
1	1
2	2
3	4
4	12
5	34
6	118
7	396
8	1508
9	5670
10	22773
11	91337
12	381157
13	1597683
14	6855957
15	29599117
16	129748149
17	572349631
18	2551033858
19	11435935450
20	51651644306
21	234472103672
22	1070461943299
23	4908349870799
24	22607570625188
25	104515879798724
26	484955119433493

[1, 1, 2, 4, 12, 34, 118, 396, 1508, 5670, 22773, 91337, 381157, 1597683, 6855957, 29599117, 129748149, 572349631, 2551033858, 11435935450, 51651644306, 234472103672, 1070461943299, 4908349870799, 22607570625188, 104515879798724, 484955119433493]

cp's OEIS Frontend

A240904 Number of lattice paths from (0,0) to (n,0) that do not go below the x-axis or above the diagonal x=y and consist of steps u=(1,1), U=(1,3), H=(1,0), d=(1,-1) and D=(1,-3).

Table of values

List of values