| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 10 |
| 7 | 29 |
| 8 | 100 |
| 9 | 387 |
| 10 | 2276 |
| 11 | 17581 |
| 12 | 155034 |
| 13 | 1632582 |
| 14 | 20304423 |
| 15 | 321404215 |
| 16 | 6545616593 |
| 17 | 163131399978 |
| 18 | 4942168957230 |
| 19 | 181963337378973 |
| 20 | 8263219425456168 |
| 21 | 468671383459094714 |
| 22 | 32913148405732346545 |
[1,1,1,1,3,10,29,100,387,2276,17581,155034, 1632582,20304423,321404215,6545616593, 163131399978,4942168957230,181963337378973, 8263219425456168,468671383459094714, 32913148405732346545] |