The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 5 |
| 4 | 12 |
| 5 | 23 |
| 6 | 51 |
| 7 | 103 |
| 8 | 221 |
| 9 | 456 |
| 10 | 965 |
| 11 | 2009 |
| 12 | 4227 |
| 13 | 8833 |
| 14 | 18540 |
| 15 | 38803 |
| 16 | 81363 |
| 17 | 170399 |
| 18 | 357145 |
| 19 | 748176 |
| 20 | 1567849 |
| 21 | 3284833 |
| 22 | 6883059 |
| 23 | 14421533 |
| 24 | 30218028 |
| 25 | 63314735 |
| 26 | 132664227 |
| 27 | 277968871 |
| 28 | 582428789 |
| 29 | 1220356440 |
| 30 | 2557009709 |
[1,1,3,5,12,23,51,103,221,456,965,2009,4227,8833, 18540,38803,81363,170399,357145,748176,1567849, 3284833,6883059,14421533,30218028,63314735, 132664227,277968871,582428789,1220356440, 2557009709] |