The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 23 |
| 5 | 51 |
| 6 | 113 |
| 7 | 249 |
| 8 | 548 |
| 9 | 1207 |
| 10 | 2655 |
| 11 | 5843 |
| 12 | 12855 |
| 13 | 28281 |
| 14 | 62218 |
| 15 | 136880 |
| 16 | 301136 |
| 17 | 662499 |
| 18 | 1457498 |
| 19 | 3206497 |
| 20 | 7054294 |
| 21 | 15519448 |
| 22 | 34142787 |
| 23 | 75114133 |
| 24 | 165251092 |
| 25 | 363552403 |
| 26 | 799815288 |
| 27 | 1759593634 |
| 28 | 3871105995 |
| 29 | 8516433190 |
[1,2,4,10,23,51,113,249,548,1207,2655,5843,12855, 28281,62218,136880,301136,662499,1457498,3206497, 7054294,15519448,34142787,75114133,165251092, 363552403,799815288,1759593634,3871105995, 8516433190] |