The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 72 |
| 4 | 120 |
| 5 | 1440 |
| 6 | 6720 |
| 7 | 28800 |
| 8 | 80640 |
| 9 | 483840 |
| 10 | 1612800 |
| 11 | 5806080 |
| 12 | 7096320 |
| 13 | 85155840 |
| 14 | 283852800 |
| 15 | 510935040 |
| 16 | 1476034560 |
| 17 | 7947878400 |
| 18 | 17712414720 |
| 19 | 29520691200 |
| 20 | 106274488320 |
| 21 | 354248294400 |
| 22 | 1653158707200 |
| 23 | 2125489766400 |
| 24 | 4817776803840 |
| 25 | 8029628006400 |
| 26 | 28906660823040 |
[1,6,72,120,1440,6720,28800,80640,483840,1612800, 5806080,7096320,85155840,283852800,510935040, 1476034560,7947878400,17712414720,29520691200, 106274488320,354248294400,1653158707200, 2125489766400,4817776803840,8029628006400, 28906660823040] |