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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 128 |
| 5 | 554 |
| 6 | 2450 |
| 7 | 11068 |
| 8 | 50454 |
| 9 | 232576 |
| 10 | 1081161 |
| 11 | 5051101 |
| 12 | 23756457 |
| 13 | 112147893 |
| 14 | 531708174 |
| 15 | 2529355830 |
| 16 | 12066683478 |
| 17 | 57726437428 |
| 18 | 276784459827 |
| 19 | 1329969198440 |
| 20 | 6402785658476 |
| 21 | 30876952919825 |
| 22 | 149140006137561 |
| 23 | 721393168587268 |
| 24 | 3494029020215602 |
| 25 | 16943804833953925 |
| 26 | 82258958531986442 |
[1,2,8,30,128,554,2450,11068,50454,232576,1081161, 5051101,23756457,112147893,531708174,2529355830, 12066683478,57726437428,276784459827, 1329969198440,6402785658476,30876952919825, 149140006137561,721393168587268,3494029020215602, 16943804833953925,82258958531986442] |