The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 484 |
| 3 | 2704 |
| 4 | 13456 |
| 5 | 64009 |
| 6 | 290521 |
| 7 | 1283689 |
| 8 | 5541316 |
| 9 | 23541904 |
| 10 | 98724096 |
| 11 | 410022001 |
| 12 | 1689785449 |
| 13 | 6922406401 |
| 14 | 28223328004 |
| 15 | 114636416400 |
| 16 | 464224195600 |
| 17 | 1875379608025 |
| 18 | 7561592527225 |
| 19 | 30441493099161 |
| 20 | 122399217842724 |
[81,484,2704,13456,64009,290521,1283689,5541316, 23541904,98724096,410022001,1689785449,6922406401, 28223328004,114636416400,464224195600, 1875379608025,7561592527225,30441493099161, 122399217842724] |