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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 7 |
| 5 | 10 |
| 6 | 11 |
| 7 | 17 |
| 8 | 20 |
| 9 | 65 |
| 10 | 70 |
| 11 | 811 |
| 12 | 947 |
| 13 | 1099 |
| 14 | 1487 |
| 15 | 1540 |
| 16 | 6617 |
| 17 | 15067 |
| 18 | 18433 |
| 19 | 19063 |
| 20 | 31462 |
| 21 | 131270 |
[1,2,4,7,10,11,17,20,65,70,811,947,1099,1487,1540, 6617,15067,18433,19063,31462,131270] |