The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 13 |
| 6 | 15 |
| 7 | 25 |
| 8 | 39 |
| 9 | 69 |
| 10 | 165 |
| 11 | 171 |
| 12 | 209 |
| 13 | 339 |
| 14 | 2033 |
| 15 | 6583 |
| 16 | 15393 |
| 17 | 282989 |
| 18 | 498483 |
| 19 | 504221 |
| 20 | 754611 |
| 21 | 864751 |
[0,1,3,9,13,15,25,39,69,165,171,209,339,2033,6583, 15393,282989,498483,504221,754611,864751] |