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 | 1 |
| 6 | 5 |
| 7 | 0 |
| 8 | 6 |
| 9 | 4 |
| 10 | 6 |
| 11 | 0 |
| 12 | 18 |
| 13 | 0 |
| 14 | 20 |
| 15 | 0 |
| 16 | 0 |
| 17 | 6 |
| 18 | 51 |
| 19 | 0 |
| 20 | 42 |
| 21 | 0 |
| 22 | 0 |
| 23 | 0 |
[1,1,1,2,1,5,0,6,4,6,0,18,0,20,0,0,6,51,0,42,0,0, 0] |