| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 27 |
| 3 | 309 |
| 4 | 4059 |
| 5 | 57753 |
| 6 | 866349 |
| 7 | 13492251 |
| 8 | 216077787 |
| 9 | 3536145057 |
| 10 | 58875891777 |
| 11 | 994150929951 |
| 12 | 16984143140589 |
| 13 | 293036113226223 |
| 14 | 5098773125244483 |
| 15 | 89368239352074309 |
| 16 | 1576424378494272987 |
| 17 | 27964450505226314673 |
| 18 | 498550055166916502121 |
[1,3,27,309,4059,57753,866349,13492251,216077787, 3536145057,58875891777,994150929951, 16984143140589,293036113226223,5098773125244483, 89368239352074309,1576424378494272987, 27964450505226314673,498550055166916502121] |