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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 9 |
| 3 | 54 |
| 4 | 486 |
| 5 | 5832 |
| 6 | 87480 |
| 7 | 1574640 |
| 8 | 33067440 |
| 9 | 793618560 |
| 10 | 21427701120 |
| 11 | 642831033600 |
| 12 | 21213424108800 |
| 13 | 763683267916800 |
| 14 | 29783647448755200 |
| 15 | 1250913192847718400 |
| 16 | 56291093678147328000 |
| 17 | 2701972496551071744000 |
| 18 | 137800597324104658944000 |
| 19 | 7441232255501651582976000 |
[3,9,54,486,5832,87480,1574640,33067440,793618560, 21427701120,642831033600,21213424108800, 763683267916800,29783647448755200, 1250913192847718400,56291093678147328000, 2701972496551071744000,137800597324104658944000, 7441232255501651582976000] |