| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 141 |
| 5 | 6533 |
| 6 | 631875 |
| 7 | 123430027 |
| 8 | 48659732725 |
| 9 | 39107797223409 |
| 10 | 64702785181953175 |
| 11 | 221636039917857648631 |
| 12 | 1575528053913118966200441 |
| 13 | 23249384407499950496231003021 |
| 14 | 711653666389829384034090082068939 |
| 15 | 45128328085994437067694854477617868995 |
[1,1,1,7,141,6533,631875,123430027,48659732725, 39107797223409,64702785181953175, 221636039917857648631,1575528053913118966200441, 23249384407499950496231003021, 711653666389829384034090082068939, 45128328085994437067694854477617868995] |