The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 21 |
| 4 | 271 |
| 5 | 5073 |
| 6 | 149931 |
| 7 | 5629933 |
| 8 | 287996871 |
| 9 | 18574155561 |
| 10 | 1472489126563 |
| 11 | 143431714523781 |
| 12 | 16629096827674623 |
| 13 | 2271941249486405761 |
| 14 | 362871752515734614811 |
| 15 | 66782754543872231839773 |
| 16 | 14054632818067589280068791 |
| 17 | 3359850327080126215443462873 |
[1,1,3,21,271,5073,149931,5629933,287996871, 18574155561,1472489126563,143431714523781, 16629096827674623,2271941249486405761, 362871752515734614811,66782754543872231839773, 14054632818067589280068791, 3359850327080126215443462873] |