The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 18 |
| 3 | 457 |
| 4 | 23672 |
| 5 | 1894385 |
| 6 | 222366990 |
| 7 | 35787014405 |
| 8 | 7577453436556 |
| 9 | 2041650829418725 |
| 10 | 682219727134076250 |
| 11 | 276875111860035807025 |
| 12 | 134154122874807259146080 |
| 13 | 76495123111877275062902585 |
| 14 | 50706144718387731766299555750 |
[1,18,457,23672,1894385,222366990,35787014405, 7577453436556,2041650829418725,682219727134076250, 276875111860035807025,134154122874807259146080, 76495123111877275062902585, 50706144718387731766299555750] |