A225042 - cp's OEIS frontend

A225042 Number of lattice paths from (0,0) to (n,n) that do not go below the x-axis or above the diagonal x=y and consist of steps U=(1,1), D=(1,-1), H=(1,0) and S=(0,1).

n	a(n)
0	1
1	2
2	8
3	48
4	360
5	3088
6	28928
7	288208
8	3003952
9	32402384
10	359019952
11	4064452272
12	46829600704
13	547498996736
14	6480275672192
15	77511461858592
16	935562094075392
17	11381614588917296
18	139425068741674448
19	1718444636265140992
20	21295889048851102176
21	265200380258393530896

[1, 2, 8, 48, 360, 3088, 28928, 288208, 3003952, 32402384, 359019952, 4064452272, 46829600704, 547498996736, 6480275672192, 77511461858592, 935562094075392, 11381614588917296, 139425068741674448, 1718444636265140992, 21295889048851102176, 265200380258393530896]

cp's OEIS Frontend

A225042 Number of lattice paths from (0,0) to (n,n) that do not go below the x-axis or above the diagonal x=y and consist of steps U=(1,1), D=(1,-1), H=(1,0) and S=(0,1).

Table of values

List of values