The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 5 |
| 5 | 10 |
| 6 | 18 |
| 7 | 45 |
| 8 | 98 |
| 9 | 242 |
| 10 | 569 |
| 11 | 1360 |
| 12 | 3101 |
| 13 | 6799 |
| 14 | 14674 |
| 15 | 31297 |
| 16 | 66483 |
| 17 | 144954 |
| 18 | 326150 |
| 19 | 787455 |
| 20 | 2019266 |
| 21 | 5425240 |
| 22 | 14793678 |
| 23 | 40049832 |
| 24 | 105958990 |
| 25 | 272562864 |
| 26 | 679336804 |
| 27 | 1644951169 |
| 28 | 3882700822 |
| 29 | 8997217790 |
| 30 | 20559767303 |
[1,1,1,3,5,10,18,45,98,242,569,1360,3101,6799, 14674,31297,66483,144954,326150,787455,2019266, 5425240,14793678,40049832,105958990,272562864, 679336804,1644951169,3882700822,8997217790, 20559767303] |