n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 60 |
3 | 350 |
4 | 1890 |
5 | 9702 |
6 | 48048 |
7 | 231660 |
8 | 1093950 |
9 | 5080790 |
10 | 23279256 |
11 | 105462084 |
12 | 473227300 |
13 | 2106121500 |
14 | 9307051200 |
15 | 40873466520 |
16 | 178520875830 |
17 | 775924068150 |
18 | 3357800061000 |
19 | 14473885526100 |
20 | 62168784497820 |
21 | 266168518910580 |
[1,9,60,350,1890,9702,48048,231660,1093950, 5080790,23279256,105462084,473227300,2106121500, 9307051200,40873466520,178520875830,775924068150, 3357800061000,14473885526100,62168784497820, 266168518910580] |