The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 26 |
| 5 | 192 |
| 6 | 3269 |
| 7 | 78117 |
| 8 | 3513962 |
| 9 | 247575648 |
| 10 | 30693247619 |
| 11 | 6179267999635 |
[1,1,4,26,192,3269,78117,3513962,247575648, 30693247619,6179267999635] |