| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 90 |
| 4 | 4137 |
| 5 | 154458 |
| 6 | 5488703 |
| 7 | 201212852 |
| 8 | 7816225089 |
| 9 | 303242246539 |
| 10 | 11670544747194 |
| 11 | 449384417173902 |
| 12 | 17313378667903125 |
| 13 | 666942058278936822 |
| 14 | 25692119785626315240 |
| 15 | 989734547009551775051 |
[0,0,90,4137,154458,5488703,201212852,7816225089, 303242246539,11670544747194,449384417173902, 17313378667903125,666942058278936822, 25692119785626315240,989734547009551775051] |