The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | -1 |
| 2 | 213 |
| 3 | 4767 |
| 4 | 52682 |
| 5 | 627573 |
| 6 | 4682412 |
| 7 | 53313931 |
| 8 | 341278995 |
| 9 | 3421674678 |
| 10 | 24687536097 |
| 11 | 214728131688 |
| 12 | 1291490582217 |
| 13 | 14602976386348 |
| 14 | 80718169058895 |
| 15 | 691486905294549 |
| 16 | 5191979939244635 |
| 17 | 44020035323951778 |
| 18 | 245857487857551822 |
| 19 | 2489942402834854279 |
| 20 | 13633673140696254618 |
[-1,213,4767,52682,627573,4682412,53313931, 341278995,3421674678,24687536097,214728131688, 1291490582217,14602976386348,80718169058895, 691486905294549,5191979939244635, 44020035323951778,245857487857551822, 2489942402834854279,13633673140696254618] |