The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 56 |
| 6 | 341 |
| 7 | 2351 |
| 8 | 17329 |
| 9 | 133126 |
| 10 | 1052813 |
| 11 | 8511339 |
| 12 | 70050568 |
| 13 | 585226579 |
| 14 | 4952310082 |
| 15 | 42376979857 |
| 16 | 366185395267 |
| 17 | 3191787761573 |
| 18 | 28036397185485 |
| 19 | 247982793594183 |
| 20 | 2207183342498485 |
| 21 | 19756959439608022 |
| 22 | 177765564883970415 |
[1,1,3,11,56,341,2351,17329,133126,1052813, 8511339,70050568,585226579,4952310082,42376979857, 366185395267,3191787761573,28036397185485, 247982793594183,2207183342498485, 19756959439608022,177765564883970415] |