The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 38 |
| 4 | 384 |
| 5 | 4425 |
| 6 | 57976 |
| 7 | 807318 |
| 8 | 11828706 |
| 9 | 179826245 |
| 10 | 2816100678 |
| 11 | 45170552490 |
| 12 | 739103543356 |
| 13 | 12297976924176 |
| 14 | 207577047945312 |
| 15 | 3547290764931730 |
| 16 | 61277684496311364 |
| 17 | 1068648890500799799 |
| 18 | 18794421104465407618 |
| 19 | 333037302131948734566 |
| 20 | 5941487005826379359448 |
[1,1,6,38,384,4425,57976,807318,11828706, 179826245,2816100678,45170552490,739103543356, 12297976924176,207577047945312,3547290764931730, 61277684496311364,1068648890500799799, 18794421104465407618,333037302131948734566, 5941487005826379359448] |