The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 5 |
| 10 | 13 |
| 11 | 25 |
| 12 | 61 |
| 13 | 195 |
| 14 | 561 |
| 15 | 1503 |
| 16 | 6349 |
| 17 | 34075 |
| 18 | 171101 |
| 19 | 895779 |
| 20 | 5615365 |
| 21 | 39425317 |
| 22 | 281937999 |
[1,1,1,1,1,1,1,1,5,13,25,61,195,561,1503,6349, 34075,171101,895779,5615365,39425317,281937999] |