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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 14 |
| 4 | 21 |
| 5 | 66 |
| 6 | 205 |
| 7 | 583 |
| 8 | 837 |
| 9 | 1259 |
| 10 | 1631 |
| 11 | 2178 |
| 12 | 6346 |
| 13 | 15851 |
| 14 | 58371 |
| 15 | 61804 |
| 16 | 129196 |
| 17 | 409879 |
| 18 | 1670753 |
[1,7,14,21,66,205,583,837,1259,1631,2178,6346, 15851,58371,61804,129196,409879,1670753] |