| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 51 |
| 4 | 425 |
| 5 | 3879 |
| 6 | 36527 |
| 7 | 355333 |
| 8 | 3531175 |
| 9 | 35673875 |
| 10 | 365179885 |
| 11 | 3777991337 |
| 12 | 39430009247 |
| 13 | 414567124053 |
| 14 | 4386228722281 |
| 15 | 46659584847835 |
| 16 | 498701253293129 |
| 17 | 5352318710976505 |
| 18 | 57655365854918487 |
| 19 | 623105208980304843 |
| 20 | 6753999316026236871 |
| 21 | 73403038257774972101 |
| 22 | 799674458063926645329 |
[1,1,7,51,425,3879,36527,355333,3531175,35673875, 365179885,3777991337,39430009247,414567124053, 4386228722281,46659584847835,498701253293129, 5352318710976505,57655365854918487, 623105208980304843,6753999316026236871, 73403038257774972101,799674458063926645329] |