The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 11 |
| 7 | 23 |
| 8 | 50 |
| 9 | 118 |
| 10 | 283 |
| 11 | 731 |
| 12 | 1921 |
| 13 | 5370 |
| 14 | 14884 |
| 15 | 43118 |
| 16 | 130509 |
| 17 | 397490 |
| 18 | 1266010 |
| 19 | 4077494 |
| 20 | 13435445 |
| 21 | 45687806 |
| 22 | 157483627 |
| 23 | 551205779 |
| 24 | 1979511990 |
[1,1,1,2,3,5,11,23,50,118,283,731,1921,5370,14884, 43118,130509,397490,1266010,4077494,13435445, 45687806,157483627,551205779,1979511990] |