The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 75 |
| 5 | 528 |
| 6 | 4584 |
| 7 | 40609 |
| 8 | 373981 |
| 9 | 3493723 |
| 10 | 33079702 |
| 11 | 316109657 |
| 12 | 3044648053 |
[1,1,3,11,75,528,4584,40609,373981,3493723, 33079702,316109657,3044648053] |