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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 16 |
| 3 | 92 |
| 4 | 508 |
| 5 | 2788 |
| 6 | 15316 |
| 7 | 84196 |
| 8 | 462940 |
| 9 | 2545492 |
| 10 | 13996468 |
| 11 | 76959844 |
| 12 | 423164812 |
| 13 | 2326777444 |
| 14 | 12793817140 |
| 15 | 70346976484 |
| 16 | 386803802332 |
| 17 | 2126845944052 |
| 18 | 11694491219668 |
| 19 | 64302318307108 |
| 20 | 353567167818892 |
| 21 | 1944093859291588 |
[2,16,92,508,2788,15316,84196,462940,2545492, 13996468,76959844,423164812,2326777444, 12793817140,70346976484,386803802332, 2126845944052,11694491219668,64302318307108, 353567167818892,1944093859291588] |