| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 16 |
| 6 | 170 |
| 7 | 1549 |
| 8 | 13253 |
| 9 | 110970 |
| 10 | 928822 |
| 11 | 7862353 |
| 12 | 67758488 |
| 13 | 596837558 |
| 14 | 5385257886 |
| 15 | 49837119320 |
| 16 | 473321736911 |
| 17 | 4614233950422 |
| 18 | 46168813528478 |
| 19 | 474017189673555 |
| 20 | 4992024759165631 |
| 21 | 53902161267878974 |
[0,0,0,1,16,170,1549,13253,110970,928822,7862353, 67758488,596837558,5385257886,49837119320, 473321736911,4614233950422,46168813528478, 474017189673555,4992024759165631, 53902161267878974] |