The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 45 |
| 3 | 189 |
| 4 | 405 |
| 5 | 31185 |
| 6 | 1658475 |
| 7 | 4209975 |
| 8 | 97692469875 |
| 9 | 65511420975 |
| 10 | 4396161144375 |
| 11 | 1613742832877175 |
| 12 | 1447106344699640625 |
| 13 | 316985199315159375 |
| 14 | 790515124238106783140625 |
| 15 | 845033408668321044046875 |
| 16 | 1693960980510228821015625 |
| 17 | 84913182070036240111050234375 |
[1,1,45,189,405,31185,1658475,4209975,97692469875, 65511420975,4396161144375,1613742832877175, 1447106344699640625,316985199315159375, 790515124238106783140625,845033408668321044046875, 1693960980510228821015625, 84913182070036240111050234375] |