The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 2 |
| 8 | 3 |
| 9 | 5 |
| 10 | 7 |
| 11 | 13 |
| 12 | 19 |
| 13 | 54 |
| 14 | 129 |
| 15 | 405 |
| 16 | 1014 |
| 17 | 3416 |
| 18 | 8953 |
| 19 | 35203 |
| 20 | 121647 |
| 21 | 602370 |
| 22 | 2444491 |
| 23 | 14100721 |
| 24 | 64488491 |
| 25 | 418264276 |
| 26 | 2289523483 |
[1,1,1,1,1,1,2,3,5,7,13,19,54,129,405,1014,3416, 8953,35203,121647,602370,2444491,14100721, 64488491,418264276,2289523483] |