The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 1 |
| 6 | 75 |
| 7 | 0 |
| 8 | 1 |
| 9 | 399 |
| 10 | 4470 |
| 11 | 0 |
| 12 | 1 |
| 13 | 927 |
| 14 | 90390 |
| 15 | 224810 |
| 16 | 0 |
| 17 | 1 |
| 18 | 1815 |
| 19 | 424374 |
[0,0,1,0,1,75,0,1,399,4470,0,1,927,90390,224810,0, 1,1815,424374] |