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| n | a(n) |
|---|---|
| 7 | 1 |
| 8 | 16 |
| 9 | 144 |
| 10 | 960 |
| 11 | 5280 |
| 12 | 25344 |
| 13 | 109824 |
| 14 | 439296 |
| 15 | 1647360 |
| 16 | 5857280 |
| 17 | 19914752 |
| 18 | 65175552 |
| 19 | 206389248 |
| 20 | 635043840 |
| 21 | 1905131520 |
| 22 | 5588385792 |
| 23 | 16066609152 |
| 24 | 45364543488 |
| 25 | 126012620800 |
| 26 | 344876646400 |
| 27 | 931166945280 |
| 28 | 2483111854080 |
[1,16,144,960,5280,25344,109824,439296,1647360, 5857280,19914752,65175552,206389248,635043840, 1905131520,5588385792,16066609152,45364543488, 126012620800,344876646400,931166945280, 2483111854080] |