The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 247 |
| 4 | 28248 |
| 5 | 12075849 |
| 6 | 19261290694 |
| 7 | 114545399709628 |
| 8 | 2540187335598061548 |
| 9 | 210067171005687284366855 |
| 10 | 64781669533557315098076107091 |
[1,8,247,28248,12075849,19261290694, 114545399709628,2540187335598061548, 210067171005687284366855, 64781669533557315098076107091] |