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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 65 |
| 5 | 237 |
| 6 | 903 |
| 7 | 3626 |
| 8 | 14822 |
| 9 | 60668 |
| 10 | 252632 |
| 11 | 1066726 |
| 12 | 4542198 |
| 13 | 19459068 |
| 14 | 83952935 |
| 15 | 364404201 |
| 16 | 1590499390 |
| 17 | 6973481584 |
| 18 | 30691951800 |
| 19 | 135582966112 |
| 20 | 601142785215 |
| 21 | 2673652685169 |
| 22 | 11922615242208 |
| 23 | 53301912197676 |
| 24 | 238892225367457 |
| 25 | 1073099767854329 |
| 26 | 4829893177660861 |
| 27 | 21779307506270372 |
[1,2,5,17,65,237,903,3626,14822,60668,252632, 1066726,4542198,19459068,83952935,364404201, 1590499390,6973481584,30691951800,135582966112, 601142785215,2673652685169,11922615242208, 53301912197676,238892225367457,1073099767854329, 4829893177660861,21779307506270372] |