A145600 - cp's OEIS frontend

A145600 a(n) is the number of walks from (0,0) to (0,1) that remain in the upper half-plane y >= 0 using (2*n - 1) unit steps either up (U), down (D), left (L) or right (R).

n	a(n)
1	1
2	8
3	75
4	784
5	8820
6	104544
7	1288287
8	16359200
9	212751396
10	2821056160
11	38013731756
12	519227905728
13	7174705330000
14	100136810390400
15	1409850293610375
16	20002637245262400
17	285732116760449700

[1, 8, 75, 784, 8820, 104544, 1288287, 16359200, 212751396, 2821056160, 38013731756, 519227905728, 7174705330000, 100136810390400, 1409850293610375, 20002637245262400, 285732116760449700]

cp's OEIS Frontend

A145600 a(n) is the number of walks from (0,0) to (0,1) that remain in the upper half-plane y >= 0 using (2*n - 1) unit steps either up (U), down (D), left (L) or right (R).

Table of values

List of values