| n | a(n) |
|---|---|
| 5 | 1 |
| 6 | 6 |
| 7 | 63 |
| 8 | 560 |
| 9 | 5922 |
| 10 | 61992 |
| 11 | 739662 |
| 12 | 9086616 |
| 13 | 122792670 |
| 14 | 1741884144 |
| 15 | 26631631026 |
| 16 | 428931318816 |
| 17 | 7362963616008 |
| 18 | 132977285400960 |
| 19 | 2538822785931432 |
| 20 | 50863863365419104 |
| 21 | 1070731366348427784 |
| 22 | 23576426902769412672 |
| 23 | 542918591829347774040 |
| 24 | 13035693339696004705728 |
[1,6,63,560,5922,61992,739662,9086616,122792670, 1741884144,26631631026,428931318816,7362963616008, 132977285400960,2538822785931432, 50863863365419104,1070731366348427784, 23576426902769412672,542918591829347774040, 13035693339696004705728] |