The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 22 |
| 5 | 94 |
| 6 | 340 |
| 7 | 1579 |
| 8 | 6118 |
| 9 | 29746 |
| 10 | 120060 |
| 11 | 600934 |
| 12 | 2492028 |
| 13 | 12725756 |
| 14 | 53798888 |
| 15 | 278786739 |
| 16 | 1195684230 |
| 17 | 6265816042 |
| 18 | 27175425004 |
| 19 | 143671870034 |
| 20 | 628705751828 |
| 21 | 3347680236132 |
| 22 | 14756641134872 |
| 23 | 79039468217086 |
| 24 | 350529497005532 |
| 25 | 1886818634445044 |
| 26 | 8410852483002200 |
[1,1,2,7,22,94,340,1579,6118,29746,120060,600934, 2492028,12725756,53798888,278786739,1195684230, 6265816042,27175425004,143671870034,628705751828, 3347680236132,14756641134872,79039468217086, 350529497005532,1886818634445044,8410852483002200] |