The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 21 |
| 5 | 81 |
| 6 | 147 |
| 7 | 441 |
| 8 | 903 |
| 9 | 2499 |
| 10 | 6069 |
| 11 | 15351 |
| 12 | 29095 |
| 13 | 80367 |
| 14 | 153065 |
| 15 | 366025 |
| 16 | 643885 |
[1,3,9,21,81,147,441,903,2499,6069,15351,29095, 80367,153065,366025,643885] |