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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 13 |
| 5 | 26 |
| 6 | 39 |
| 7 | 277 |
| 8 | 642 |
| 9 | 2291 |
| 10 | 4582 |
| 11 | 6231 |
| 12 | 16402 |
| 13 | 26573 |
| 14 | 36744 |
| 15 | 63317 |
| 16 | 73488 |
| 17 | 110232 |
| 18 | 414355 |
| 19 | 828710 |
[1,3,6,13,26,39,277,642,2291,4582,6231,16402, 26573,36744,63317,73488,110232,414355,828710] |