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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 7 |
| 4 | 20 |
| 5 | 68 |
| 6 | 320 |
| 7 | 352 |
| 8 | 1088 |
| 9 | 3136 |
| 10 | 5184 |
| 11 | 13376 |
| 12 | 16704 |
| 13 | 17472 |
| 14 | 70720 |
| 15 | 82240 |
| 16 | 83008 |
| 17 | 90112 |
| 18 | 90176 |
[1,4,7,20,68,320,352,1088,3136,5184,13376,16704, 17472,70720,82240,83008,90112,90176] |