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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 24 |
| 5 | 42 |
| 6 | 60 |
| 7 | 132 |
| 8 | 303 |
| 9 | 312 |
| 10 | 450 |
| 11 | 564 |
| 12 | 1236 |
| 13 | 1419 |
| 14 | 2952 |
| 15 | 10098 |
| 16 | 12060 |
| 17 | 13848 |
| 18 | 17229 |
| 19 | 22356 |
| 20 | 37896 |
| 21 | 251904 |
[1,3,12,24,42,60,132,303,312,450,564,1236,1419, 2952,10098,12060,13848,17229,22356,37896,251904] |