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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 12 |
| 4 | 76 |
| 5 | 252 |
| 6 | 76 |
| 7 | 492 |
| 8 | 6104 |
| 9 | 6104 |
| 10 | 492 |
| 11 | 3212 |
| 12 | 153222 |
| 13 | 636636 |
| 14 | 153222 |
| 15 | 3212 |
| 16 | 21036 |
| 17 | 3935188 |
| 18 | 72691500 |
| 19 | 72691500 |
| 20 | 3935188 |
| 21 | 21036 |
| 22 | 137932 |
| 23 | 101884208 |
| 24 | 8603604942 |
[2,12,12,76,252,76,492,6104,6104,492,3212,153222, 636636,153222,3212,21036,3935188,72691500, 72691500,3935188,21036,137932,101884208, 8603604942] |