| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 25 |
| 3 | 121 |
| 4 | 2881 |
| 5 | 23521 |
| 6 | 484681 |
| 7 | 5223625 |
| 8 | 97949041 |
| 9 | 1243490161 |
| 10 | 22061635465 |
| 11 | 309799010665 |
| 12 | 5331441539425 |
| 13 | 79799232449665 |
| 14 | 1352284119871465 |
| 15 | 21095036702450281 |
| 16 | 355125946871044561 |
| 17 | 5694209222592780625 |
| 18 | 95705961654403180201 |
| 19 | 1563714140278617173641 |
| 20 | 26311422169994777663761 |
[1,1,25,121,2881,23521,484681,5223625,97949041, 1243490161,22061635465,309799010665,5331441539425, 79799232449665,1352284119871465,21095036702450281, 355125946871044561,5694209222592780625, 95705961654403180201,1563714140278617173641, 26311422169994777663761] |