The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 21 |
| 3 | 345 |
| 4 | 10625 |
| 5 | 74375 |
| 6 | 860625 |
| 7 | 84189105 |
| 8 | 1599592995 |
| 9 | 23993894925 |
[3,21,345,10625,74375,860625,84189105,1599592995, 23993894925] |