The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 28 |
| 4 | 427 |
| 5 | 9096 |
| 6 | 248298 |
| 7 | 8258552 |
| 8 | 323891811 |
| 9 | 14636853712 |
| 10 | 749171687006 |
| 11 | 42853503567480 |
| 12 | 2710099789775566 |
| 13 | 187811949192251632 |
| 14 | 14156747168376595956 |
| 15 | 1153316446792123524144 |
| 16 | 100995199848878125787555 |
| 17 | 9461277820648354922926368 |
| 18 | 944228520086488255850280918 |
[1,1,3,28,427,9096,248298,8258552,323891811, 14636853712,749171687006,42853503567480, 2710099789775566,187811949192251632, 14156747168376595956,1153316446792123524144, 100995199848878125787555, 9461277820648354922926368, 944228520086488255850280918] |