The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 61 |
| 5 | 273 |
| 6 | 1228 |
| 7 | 5631 |
| 8 | 26141 |
| 9 | 123261 |
| 10 | 589251 |
| 11 | 2855815 |
| 12 | 14021038 |
| 13 | 69707192 |
[1,3,14,61,273,1228,5631,26141,123261,589251, 2855815,14021038,69707192] |