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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 22 |
| 4 | 71 |
| 5 | 228 |
| 6 | 733 |
| 7 | 2356 |
| 8 | 7573 |
| 9 | 24342 |
| 10 | 78243 |
| 11 | 251498 |
| 12 | 808395 |
| 13 | 2598440 |
| 14 | 8352217 |
| 15 | 26846696 |
| 16 | 86293865 |
| 17 | 277376074 |
| 18 | 891575391 |
| 19 | 2865808382 |
| 20 | 9211624463 |
| 21 | 29609106380 |
| 22 | 95173135221 |
| 23 | 305916887580 |
| 24 | 983314691581 |
| 25 | 3160687827102 |
| 26 | 10159461285307 |
| 27 | 32655756991442 |
[1,2,7,22,71,228,733,2356,7573,24342,78243,251498, 808395,2598440,8352217,26846696,86293865, 277376074,891575391,2865808382,9211624463, 29609106380,95173135221,305916887580,983314691581, 3160687827102,10159461285307,32655756991442] |