The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 25 |
| 6 | 80 |
| 7 | 262 |
| 8 | 1003 |
| 9 | 4044 |
| 10 | 17983 |
| 11 | 87516 |
| 12 | 506509 |
| 13 | 3820831 |
| 14 | 41827385 |
[1,2,4,10,25,80,262,1003,4044,17983,87516,506509, 3820831,41827385] |