The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 18 |
| 4 | 518 |
| 5 | 23610 |
| 6 | 1600982 |
| 7 | 150451098 |
| 8 | 18694217558 |
| 9 | 2966151496410 |
| 10 | 584994048653462 |
| 11 | 140357794553191578 |
| 12 | 40253455215544778198 |
| 13 | 13598018000464234802010 |
| 14 | 5343837921922909297592342 |
[1,0,2,18,518,23610,1600982,150451098,18694217558, 2966151496410,584994048653462,140357794553191578, 40253455215544778198,13598018000464234802010, 5343837921922909297592342] |