n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 26 |
5 | 143 |
6 | 880 |
7 | 6820 |
8 | 61270 |
9 | 612700 |
10 | 6740700 |
11 | 83088500 |
12 | 1211283600 |
13 | 17058212600 |
14 | 270017301300 |
15 | 4560302022000 |
16 | 82065335385000 |
17 | 1648341372414000 |
18 | 34076827548280000 |
19 | 725735500635080000 |
20 | 17178403115182870000 |
[1,1,2,6,26,143,880,6820,61270,612700,6740700, 83088500,1211283600,17058212600,270017301300, 4560302022000,82065335385000,1648341372414000, 34076827548280000,725735500635080000, 17178403115182870000] |