The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 25 |
| 5 | 80 |
| 6 | 268 |
| 7 | 923 |
| 8 | 3245 |
| 9 | 11598 |
| 10 | 42035 |
| 11 | 153962 |
| 12 | 568956 |
| 13 | 2118875 |
| 14 | 7941310 |
| 15 | 29924675 |
| 16 | 113311965 |
| 17 | 430839470 |
| 18 | 1644074844 |
| 19 | 6294293928 |
| 20 | 24166315996 |
| 21 | 93020242891 |
| 22 | 358881594364 |
| 23 | 1387458654657 |
| 24 | 5374008713314 |
| 25 | 20850681546782 |
| 26 | 81023879671151 |
| 27 | 315296265177696 |
| 28 | 1228546417915060 |
| 29 | 4792715751016104 |
[1,1,3,8,25,80,268,923,3245,11598,42035,153962, 568956,2118875,7941310,29924675,113311965, 430839470,1644074844,6294293928,24166315996, 93020242891,358881594364,1387458654657, 5374008713314,20850681546782,81023879671151, 315296265177696,1228546417915060,4792715751016104] |