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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 66 |
| 4 | 463 |
| 5 | 3243 |
| 6 | 22704 |
| 7 | 158929 |
| 8 | 1112505 |
| 9 | 7787538 |
| 10 | 54512767 |
| 11 | 381589371 |
| 12 | 2671125600 |
| 13 | 18697879201 |
| 14 | 130885154409 |
| 15 | 916196080866 |
| 16 | 6413372566063 |
| 17 | 44893607962443 |
| 18 | 314255255737104 |
| 19 | 2199786790159729 |
[1,9,66,463,3243,22704,158929,1112505,7787538, 54512767,381589371,2671125600,18697879201, 130885154409,916196080866,6413372566063, 44893607962443,314255255737104,2199786790159729] |