| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 84 |
| 5 | 715 |
| 6 | 7973 |
| 7 | 107800 |
| 8 | 1703453 |
| 9 | 30771149 |
| 10 | 625350597 |
| 11 | 14120901982 |
| 12 | 350747144465 |
| 13 | 9504174989803 |
| 14 | 278995251177113 |
| 15 | 8819904482341820 |
| 16 | 298740549795954189 |
| 17 | 10793273784602715481 |
| 18 | 414325010484102619421 |
[1,2,5,15,84,715,7973,107800,1703453,30771149, 625350597,14120901982,350747144465,9504174989803, 278995251177113,8819904482341820, 298740549795954189,10793273784602715481, 414325010484102619421] |