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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 13 |
| 3 | 89 |
| 4 | 610 |
| 5 | 4181 |
| 6 | 28657 |
| 7 | 196418 |
| 8 | 1346269 |
| 9 | 9227465 |
| 10 | 63245986 |
| 11 | 433494437 |
| 12 | 2971215073 |
| 13 | 20365011074 |
| 14 | 139583862445 |
| 15 | 956722026041 |
| 16 | 6557470319842 |
| 17 | 44945570212853 |
| 18 | 308061521170129 |
| 19 | 2111485077978050 |
| 20 | 14472334024676221 |
[1,2,13,89,610,4181,28657,196418,1346269,9227465, 63245986,433494437,2971215073,20365011074, 139583862445,956722026041,6557470319842, 44945570212853,308061521170129,2111485077978050, 14472334024676221] |