The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 16 |
| 4 | 1321 |
| 5 | 317264 |
| 6 | 295326468 |
| 7 | 990266635029 |
| 8 | 12088043573966128 |
| 9 | 535440346291887704215 |
[0,3,16,1321,317264,295326468,990266635029, 12088043573966128,535440346291887704215] |