The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 4 |
| 6 | 4 |
| 7 | 7 |
| 8 | 7 |
| 9 | 8 |
| 10 | 9 |
| 11 | 10 |
| 12 | 11 |
| 13 | 12 |
| 14 | 15 |
| 15 | 15 |
| 16 | 16 |
| 17 | 18 |
| 18 | 18 |
| 19 | 19 |
| 20 | 21 |
| 21 | 22 |
| 22 | 22 |
[0,0,1,1,3,4,4,7,7,8,9,10,11,12,15,15,16,18,18,19, 21,22,22] |