The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 84 |
| 4 | 612 |
| 5 | 4532 |
| 6 | 33762 |
| 7 | 252106 |
| 8 | 1884120 |
| 9 | 14084674 |
| 10 | 105295512 |
| 11 | 787178752 |
[2,12,84,612,4532,33762,252106,1884120,14084674, 105295512,787178752] |