The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 20 |
| 3 | 1680 |
| 4 | 367262 |
| 5 | 165022063 |
| 6 | 132375585604 |
| 7 | 172527174986381 |
| 8 | 341425620652837589 |
[1,20,1680,367262,165022063,132375585604, 172527174986381,341425620652837589] |