n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 2 |
4 | 4 |
5 | 10 |
6 | 30 |
7 | 100 |
8 | 380 |
9 | 1600 |
10 | 7400 |
11 | 37400 |
12 | 204600 |
13 | 1205600 |
14 | 7612000 |
15 | 51260000 |
16 | 366784000 |
17 | 2778820000 |
18 | 22222332000 |
19 | 187067320000 |
20 | 1653461480000 |
21 | 15310662400000 |
22 | 148217381840000 |
23 | 1497226615280000 |
24 | 15754506226800000 |
25 | 172407188412800000 |
[1,1,1,2,4,10,30,100,380,1600,7400,37400,204600, 1205600,7612000,51260000,366784000,2778820000, 22222332000,187067320000,1653461480000, 15310662400000,148217381840000,1497226615280000, 15754506226800000,172407188412800000] |