The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | 4 |
| 7 | 3 |
| 8 | 2 |
| 9 | 0 |
| 10 | 30 |
| 11 | 40 |
| 12 | 27 |
| 13 | 17 |
| 14 | 0 |
| 15 | 546 |
| 16 | 1365 |
| 17 | 1842 |
| 18 | 1690 |
| 19 | 1451 |
| 20 | 0 |
| 21 | 41334 |
[1,1,0,1,1,0,4,3,2,0,30,40,27,17,0,546,1365,1842, 1690,1451,0,41334] |