n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 18 |
4 | 64 |
5 | 230 |
6 | 936 |
7 | 3822 |
8 | 17344 |
9 | 78354 |
10 | 389280 |
11 | 1913010 |
12 | 10267776 |
13 | 54235350 |
14 | 311348352 |
15 | 1751907150 |
16 | 10673326080 |
17 | 63531238050 |
18 | 408231498240 |
19 | 2556121021650 |
20 | 17236028160000 |
21 | 113006008398150 |
22 | 796296326031360 |
23 | 5445783239554350 |
24 | 39959419088977920 |
25 | 284127133728611250 |
[1,2,6,18,64,230,936,3822,17344,78354,389280, 1913010,10267776,54235350,311348352,1751907150, 10673326080,63531238050,408231498240, 2556121021650,17236028160000,113006008398150, 796296326031360,5445783239554350, 39959419088977920,284127133728611250] |