The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 8 |
| 3 | 320 |
| 4 | 43264 |
| 5 | 22003712 |
| 6 | 43090149376 |
| 7 | 326720427917312 |
| 8 | 9588057159626653696 |
| 9 | 1086099857128493963804672 |
[0,8,320,43264,22003712,43090149376, 326720427917312,9588057159626653696, 1086099857128493963804672] |