| n | a(n) |
|---|---|
| 3 | 6 |
| 4 | 72 |
| 5 | 720 |
| 6 | 7200 |
| 7 | 75600 |
| 8 | 846720 |
| 9 | 10160640 |
| 10 | 130636800 |
| 11 | 1796256000 |
| 12 | 26345088000 |
| 13 | 410983372800 |
| 14 | 6799906713600 |
| 15 | 118998367488000 |
| 16 | 2196892938240000 |
| 17 | 42682491371520000 |
| 18 | 870722823979008000 |
| 19 | 18611700362551296000 |
| 20 | 416026243398205440000 |
[6,72,720,7200,75600,846720,10160640,130636800, 1796256000,26345088000,410983372800,6799906713600, 118998367488000,2196892938240000, 42682491371520000,870722823979008000, 18611700362551296000,416026243398205440000] |