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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 38 |
| 4 | 200 |
| 5 | 1122 |
| 6 | 6576 |
| 7 | 39790 |
| 8 | 246672 |
| 9 | 1558658 |
| 10 | 10001592 |
| 11 | 64997814 |
| 12 | 426922392 |
| 13 | 2829624514 |
| 14 | 18901301984 |
| 15 | 127115260894 |
| 16 | 859978039840 |
| 17 | 5848754717314 |
| 18 | 39964745880552 |
| 19 | 274231943135686 |
| 20 | 1888891689752680 |
| 21 | 13055393137141282 |
| 22 | 90517646431869328 |
[1,2,8,38,200,1122,6576,39790,246672,1558658, 10001592,64997814,426922392,2829624514, 18901301984,127115260894,859978039840, 5848754717314,39964745880552,274231943135686, 1888891689752680,13055393137141282, 90517646431869328] |