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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 19 |
| 3 | 79 |
| 4 | 331 |
| 5 | 751 |
| 6 | 1171 |
| 7 | 7459 |
| 8 | 10651 |
| 9 | 18379 |
| 10 | 78439 |
| 11 | 78439 |
| 12 | 399499 |
| 13 | 644869 |
| 14 | 1427911 |
| 15 | 1427911 |
| 16 | 4355311 |
| 17 | 5715319 |
| 18 | 43030381 |
| 19 | 43030381 |
| 20 | 163384621 |
[7,19,79,331,751,1171,7459,10651,18379,78439, 78439,399499,644869,1427911,1427911,4355311, 5715319,43030381,43030381,163384621] |