The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 27 |
| 4 | 274 |
| 5 | 3874 |
| 6 | 71995 |
| 7 | 1682448 |
| 8 | 47840813 |
| 9 | 1615315141 |
| 10 | 63566760077 |
| 11 | 2873099980637 |
| 12 | 147384910116793 |
| 13 | 8496500896980637 |
| 14 | 545845612016485842 |
| 15 | 38797966029876716897 |
| 16 | 3032005571734589578076 |
[1,1,4,27,274,3874,71995,1682448,47840813, 1615315141,63566760077,2873099980637, 147384910116793,8496500896980637, 545845612016485842,38797966029876716897, 3032005571734589578076] |