The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 2 |
| 6 | 4 |
| 7 | 4 |
| 8 | 6 |
| 9 | 8 |
| 10 | 10 |
| 11 | 12 |
| 12 | 13 |
| 13 | 20 |
| 14 | 20 |
| 15 | 29 |
| 16 | 30 |
| 17 | 41 |
| 18 | 41 |
| 19 | 56 |
| 20 | 53 |
| 21 | 81 |
| 22 | 75 |
[1,1,1,2,2,4,4,6,8,10,12,13,20,20,29,30,41,41,56, 53,81,75] |