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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 64 |
| 5 | 341 |
| 6 | 1913 |
| 7 | 11132 |
| 8 | 66573 |
| 9 | 406653 |
| 10 | 2526351 |
| 11 | 15913347 |
| 12 | 101396034 |
| 13 | 652378120 |
| 14 | 4232439734 |
| 15 | 27657380019 |
| 16 | 181872596607 |
| 17 | 1202641671293 |
| 18 | 7991878198287 |
| 19 | 53343146808137 |
| 20 | 357464739709920 |
| 21 | 2404073823950915 |
[1,3,13,64,341,1913,11132,66573,406653,2526351, 15913347,101396034,652378120,4232439734, 27657380019,181872596607,1202641671293, 7991878198287,53343146808137,357464739709920, 2404073823950915] |